added pcre16 project

git-svn-id: http://svn.miranda-ng.org/main/trunk@10019 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c

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diff --git a/plugins/Pcre16/docs/ChangeLog b/plugins/Pcre16/docs/ChangeLog
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+ChangeLog for PCRE
+------------------
+
+Version 8.35 04-April-2014
+--------------------------
+
+1.  A new flag is set, when property checks are present in an XCLASS.
+    When this flag is not set, PCRE can perform certain optimizations
+    such as studying these XCLASS-es.
+
+2.  The auto-possessification of character sets were improved: a normal
+    and an extended character set can be compared now. Furthermore
+    the JIT compiler optimizes more character set checks.
+
+3.  Got rid of some compiler warnings for potentially uninitialized variables
+    that show up only when compiled with -O2.
+
+4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
+    of a match later then the end of the match. The pcretest program was not
+    handling the case sensibly - it was outputting from the start to the next
+    binary zero. It now reports this situation in a message, and outputs the
+    text from the end to the start.
+
+5.  Fast forward search is improved in JIT. Instead of the first three
+    characters, any three characters with fixed position can be searched.
+    Search order: first, last, middle.
+
+6.  Improve character range checks in JIT. Characters are read by an inprecise
+    function now, which returns with an unknown value if the character code is
+    above a certain treshold (e.g: 256). The only limitation is that the value
+    must be bigger than the treshold as well. This function is useful, when
+    the characters above the treshold are handled in the same way.
+
+7.  The macros whose names start with RAWUCHAR are placeholders for a future
+    mode in which only the bottom 21 bits of 32-bit data items are used. To
+    make this more memorable for those maintaining the code, the names have
+    been changed to start with UCHAR21, and an extensive comment has been added
+    to their definition.
+
+8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
+    to the export list in Makefile.am (they were accidentally omitted from the
+    8.34 tarball).
+
+9.  The informational output from pcretest used the phrase "starting byte set"
+    which is inappropriate for the 16-bit and 32-bit libraries. As the output
+    for "first char" and "need char" really means "non-UTF-char", I've changed
+    "byte" to "char", and slightly reworded the output. The documentation about
+    these values has also been (I hope) clarified.
+
+10. Another JIT related optimization: use table jumps for selecting the correct
+    backtracking path, when more than four alternatives are present inside a
+    bracket.
+
+11. Empty match is not possible, when the minimum length is greater than zero,
+    and there is no \K in the pattern. JIT should avoid empty match checks in
+    such cases.
+
+12. In a caseless character class with UCP support, when a character with more
+    than one alternative case was not the first character of a range, not all
+    the alternative cases were added to the class. For example, s and \x{17f}
+    are both alternative cases for S: the class [RST] was handled correctly,
+    but [R-T] was not.
+
+13. The configure.ac file always checked for pthread support when JIT was
+    enabled. This is not used in Windows, so I have put this test inside a
+    check for the presence of windows.h (which was already tested for).
+
+14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
+    The algorithm provides a way to skip certain starting offsets, and usually
+    faster than linear prefix searches.
+
+15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
+    as for 'fr_FR' and 'french'. For some reason, however, it then used the
+    Windows-specific input and output files, which have 'french' screwed in.
+    So this could never have worked. One of the problems with locales is that
+    they aren't always the same. I have now updated RunTest so that it checks
+    the output of the locale test (test 3) against three different output
+    files, and it allows the test to pass if any one of them matches. With luck
+    this should make the test pass on some versions of Solaris where it was
+    failing. Because of the uncertainty, the script did not used to stop if
+    test 3 failed; it now does. If further versions of a French locale ever
+    come to light, they can now easily be added.
+
+16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
+    there was a message during ./configure, but it did not stop. This now
+    provokes an error. The invalid example in README has been corrected.
+    If a value less than the minimum is given, the minimum value has always
+    been used, but now a warning is given.
+
+17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
+    was a bug in the test system, which is now fixed. Also, the list of various
+    configurations that are tested for each release did not have one with both
+    16/32 bits and --enable-bar-anycrlf. It now does.
+
+18. pcretest was missing "-C bsr" for displaying the \R default setting.
+
+19. Little endian PowerPC systems are supported now by the JIT compiler.
+
+20. The fast forward newline mechanism could enter to an infinite loop on
+    certain invalid UTF-8 input. Although we don't support these cases
+    this issue can be fixed by a performance optimization.
+
+21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
+    not take account if existing stack usage. There is now a new global
+    variable called pcre_stack_guard that can be set to point to an external
+    function to check stack availability. It is called at the start of
+    processing every parenthesized group.
+
+22. A typo in the code meant that in ungreedy mode the max/min qualifier
+    behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
+    not match "ab".
+
+23. When UTF was disabled, the JIT program reported some incorrect compile
+    errors. These messages are silenced now.
+
+24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
+    compiler.
+
+25. Change all the temporary files used in RunGrepTest to be different to those
+    used by RunTest so that the tests can be run simultaneously, for example by
+    "make -j check".
+
+
+Version 8.34 15-December-2013
+-----------------------------
+
+1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
+    executable memory. Patch inspired by Carsten Klein.
+
+2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
+    this macro is never tested and has no effect, because the work to support
+    coverage involves only compiling and linking options and special targets in
+    the Makefile. The comment in config.h implied that defining the macro would
+    enable coverage support, which is totally false. There was also support for
+    setting this macro in the CMake files (my fault, I just copied it from
+    configure). SUPPORT_GCOV has now been removed.
+
+3.  Make a small performance improvement in strlen16() and strlen32() in
+    pcretest.
+
+4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
+    detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
+    these cases). There was also one in pcretest.c.
+
+5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
+
+6.  In UTF mode, the code for checking whether a group could match an empty
+    string (which is used for indefinitely repeated groups to allow for
+    breaking an infinite loop) was broken when the group contained a repeated
+    negated single-character class with a character that occupied more than one
+    data item and had a minimum repetition of zero (for example, [^\x{100}]* in
+    UTF-8 mode). The effect was undefined: the group might or might not be
+    deemed as matching an empty string, or the program might have crashed.
+
+7.  The code for checking whether a group could match an empty string was not
+    recognizing that \h, \H, \v, \V, and \R must match a character.
+
+8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
+    an empty string. If it can, pcretest shows this in its information output.
+
+9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
+    that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
+    matched by pcre_exec() without using JIT:
+
+    (a) If the rest of the pattern did not match after a maximal run of
+        grapheme clusters, the code for backing up to try with fewer of them
+        did not always back up over a full grapheme when characters that do not
+        have the modifier quality were involved, e.g. Hangul syllables.
+
+    (b) If the match point in a subject started with modifier character, and
+        there was no match, the code could incorrectly back up beyond the match
+        point, and potentially beyond the first character in the subject,
+        leading to a segfault or an incorrect match result.
+
+10. A conditional group with an assertion condition could lead to PCRE
+    recording an incorrect first data item for a match if no other first data
+    item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
+    first data item, and therefore matched "ca" after "c" instead of at the
+    start.
+
+11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
+    bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
+
+12. The source of pcregrep now includes z/OS-specific code so that it can be
+    compiled for z/OS as part of the special z/OS distribution.
+
+13. Added the -T and -TM options to pcretest.
+
+14. The code in pcre_compile.c for creating the table of named capturing groups
+    has been refactored. Instead of creating the table dynamically during the
+    actual compiling pass, the information is remembered during the pre-compile
+    pass (on the stack unless there are more than 20 named groups, in which
+    case malloc() is used) and the whole table is created before the actual
+    compile happens. This has simplified the code (it is now nearly 150 lines
+    shorter) and prepared the way for better handling of references to groups
+    with duplicate names.
+
+15. A back reference to a named subpattern when there is more than one of the
+    same name now checks them in the order in which they appear in the pattern.
+    The first one that is set is used for the reference. Previously only the
+    first one was inspected. This change makes PCRE more compatible with Perl.
+
+16. Unicode character properties were updated from Unicode 6.3.0.
+
+17. The compile-time code for auto-possessification has been refactored, based
+    on a patch by Zoltan Herczeg. It now happens after instead of during
+    compilation. The code is cleaner, and more cases are handled. The option
+    PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
+    options in pcretest are provided to set it. It can also be set by
+    (*NO_AUTO_POSSESS) at the start of a pattern.
+
+18. The character VT has been added to the default ("C" locale) set of
+    characters that match \s and are generally treated as white space,
+    following this same change in Perl 5.18. There is now no difference between
+    "Perl space" and "POSIX space". Whether VT is treated as white space in
+    other locales depends on the locale.
+
+19. The code for checking named groups as conditions, either for being set or
+    for being recursed, has been refactored (this is related to 14 and 15
+    above). Processing unduplicated named groups should now be as fast at
+    numerical groups, and processing duplicated groups should be faster than
+    before.
+
+20. Two patches to the CMake build system, by Alexander Barkov:
+
+      (1) Replace the "source" command by "." in CMakeLists.txt because
+          "source" is a bash-ism.
+
+      (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
+          without these the CMake build does not work on Solaris.
+
+21. Perl has changed its handling of \8 and \9. If there is no previously
+    encountered capturing group of those numbers, they are treated as the
+    literal characters 8 and 9 instead of a binary zero followed by the
+    literals. PCRE now does the same.
+
+22. Following Perl, added \o{} to specify codepoints in octal, making it
+    possible to specify values greater than 0777 and also making them
+    unambiguous.
+
+23. Perl now gives an error for missing closing braces after \x{... instead of
+    treating the string as literal. PCRE now does the same.
+
+24. RunTest used to grumble if an inappropriate test was selected explicitly,
+    but just skip it when running all tests. This make it awkward to run ranges
+    of tests when one of them was inappropriate. Now it just skips any
+    inappropriate tests, as it always did when running all tests.
+
+25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
+    character types such as \d or \w, too many callouts were inserted, and the
+    data that they returned was rubbish.
+
+26. In UCP mode, \s was not matching two of the characters that Perl matches,
+    namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
+    were matched by \h. The code has now been refactored so that the lists of
+    the horizontal and vertical whitespace characters used for \h and \v (which
+    are defined only in one place) are now also used for \s.
+
+27. Add JIT support for the 64 bit TileGX architecture.
+    Patch by Jiong Wang (Tilera Corporation).
+
+28. Possessive quantifiers for classes (both explicit and automatically
+    generated) now use special opcodes instead of wrapping in ONCE brackets.
+
+29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
+    (because it's meaningless), this was not happening when PCRE_CASELESS was
+    set. Not wrong, but inefficient.
+
+30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
+    properties for \w, \d, etc) is present in a test regex. Otherwise if the
+    test contains no characters greater than 255, Perl doesn't realise it
+    should be using Unicode semantics.
+
+31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
+    [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
+    does in Unicode mode.
+
+32. Added the "forbid" facility to pcretest so that putting tests into the
+    wrong test files can sometimes be quickly detected.
+
+33. There is now a limit (default 250) on the depth of nesting of parentheses.
+    This limit is imposed to control the amount of system stack used at compile
+    time. It can be changed at build time by --with-parens-nest-limit=xxx or
+    the equivalent in CMake.
+
+34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
+    errors. Perl warns for these when in warning mode, but PCRE has no facility
+    for giving warnings.
+
+35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
+    However, this was not working for (?!) because it is optimized to (*FAIL),
+    for which PCRE does not allow quantifiers. The optimization is now disabled
+    when a quantifier follows (?!). I can't see any use for this, but it makes
+    things uniform.
+
+36. Perl no longer allows group names to start with digits, so I have made this
+    change also in PCRE. It simplifies the code a bit.
+
+37. In extended mode, Perl ignores spaces before a + that indicates a
+    possessive quantifier. PCRE allowed a space before the quantifier, but not
+    before the possessive +. It now does.
+
+38. The use of \K (reset reported match start) within a repeated possessive
+    group such as (a\Kb)*+ was not working.
+
+40. Document that the same character tables must be used at compile time and
+    run time, and that the facility to pass tables to pcre_exec() and
+    pcre_dfa_exec() is for use only with saved/restored patterns.
+
+41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
+    features for Builds with MSVC:
+
+    1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
+       builds). The .rc files can be used to set FileDescription and many other
+       attributes.
+
+    2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
+       This allows higher-level build scripts which want .pdb files to avoid
+       hard-coding the exact files needed."
+
+42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
+    mean "start of word" and "end of word", respectively, as a transition aid.
+
+43. A minimizing repeat of a class containing codepoints greater than 255 in
+    non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
+    compiled to use the heap for recursion.
+
+44. Got rid of some compiler warnings for unused variables when UTF but not UCP
+    is configured.
+
+
+Version 8.33 28-May-2013
+------------------------
+
+1.  Added 'U' to some constants that are compared to unsigned integers, to
+    avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
+    variables that are added to signed variables, to ensure the result is
+    signed and can be negated.
+
+2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
+    CMake config files.
+
+3.  Revise the creation of config.h.generic so that all boolean macros are
+    #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
+    overriding via -D on the command line possible.
+
+4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
+    to unsigned int is reported to make a quite noticeable speed difference in
+    a specific Windows environment. Testing on Linux did also appear to show
+    some benefit (and it is clearly not harmful). Also fixed the definition of
+    Xop which should be unsigned.
+
+5.  Related to (4), changing the definition of the intermediate variable cc
+    in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
+    improvements.
+
+6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
+    unnecessary spaces.
+
+7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
+    and later.
+
+8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
+
+9.  Optimizing fast_forward_start_bits in JIT.
+
+10. Adding support for callouts in JIT, and fixing some issues revealed
+    during this work. Namely:
+
+    (a) Unoptimized capturing brackets incorrectly reset on backtrack.
+
+    (b) Minimum length was not checked before the matching is started.
+
+11. The value of capture_last that is passed to callouts was incorrect in some
+    cases when there was a capture on one path that was subsequently abandoned
+    after a backtrack. Also, the capture_last value is now reset after a
+    recursion, since all captures are also reset in this case.
+
+12. The interpreter no longer returns the "too many substrings" error in the
+    case when an overflowing capture is in a branch that is subsequently
+    abandoned after a backtrack.
+
+13. In the pathological case when an offset vector of size 2 is used, pcretest
+    now prints out the matched string after a yield of 0 or 1.
+
+14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
+    Only supported by the JIT compiler at the moment.
+
+15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
+
+16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
+    offset of the starting point of the matching process, provided the offsets
+    vector is large enough.
+
+17. The \A escape now records a lookbehind value of 1, though its execution
+    does not actually inspect the previous character. This is to ensure that,
+    in partial multi-segment matching, at least one character from the old
+    segment is retained when a new segment is processed. Otherwise, if there
+    are no lookbehinds in the pattern, \A might match incorrectly at the start
+    of a new segment.
+
+18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
+
+19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
+    gives some modest performance improvement in 8-bit mode.
+
+20. Added the PCRE-specific property \p{Xuc} for matching characters that can
+    be expressed in certain programming languages using Universal Character
+    Names.
+
+21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
+    which points out that "non characters" are not "characters that may not
+    appear in Unicode strings" but rather "characters that are reserved for
+    internal use and have only local meaning".
+
+22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
+    there was a conditional group that depended on an assertion, if the
+    assertion was false, the callout that immediately followed the alternation
+    in the condition was skipped when pcre_exec() was used for matching.
+
+23. Allow an explicit callout to be inserted before an assertion that is the
+    condition for a conditional group, for compatibility with automatic
+    callouts, which always insert a callout at this point.
+
+24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
+    confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
+
+25. (*PRUNE) is now supported by the JIT compiler.
+
+26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
+
+27. Fix the case where there are two or more SKIPs with arguments that may be
+    ignored.
+
+28. (*SKIP) is now supported by the JIT compiler.
+
+29. (*THEN) is now supported by the JIT compiler.
+
+30. Update RunTest with additional test selector options.
+
+31. The way PCRE handles backtracking verbs has been changed in two ways.
+
+    (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
+    SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
+    backtracking. In some cases this makes it more Perl-compatible, but Perl's
+    rather obscure rules do not always do the same thing.
+
+    (2) Previously, backtracking verbs were confined within assertions. This is
+    no longer the case for positive assertions, except for (*ACCEPT). Again,
+    this sometimes improves Perl compatibility, and sometimes does not.
+
+32. A number of tests that were in test 2 because Perl did things differently
+    have been moved to test 1, because either Perl or PCRE has changed, and
+    these tests are now compatible.
+
+32. Backtracking control verbs are now handled in the same way in JIT and
+    interpreter.
+
+33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
+    contained a forward subroutine reference caused a compile error.
+
+34. Auto-detect and optimize limited repetitions in JIT.
+
+35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
+    blocking (*UTF) etc.
+
+36. In the interpreter, maximizing pattern repetitions for characters and
+    character types now use tail recursion, which reduces stack usage.
+
+37. The value of the max lookbehind was not correctly preserved if a compiled
+    and saved regex was reloaded on a host of different endianness.
+
+38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
+    of the compiled pattern block, expand the flags field from 16 to 32 bits
+    because it was almost full.
+
+39. Try madvise first before posix_madvise.
+
+40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
+    with a pattern such as ^$. It has taken 4 years for anybody to notice! The
+    original change locked out all matches of empty strings. This has been
+    changed so that one match of an empty string per line is recognized.
+    Subsequent searches on the same line (for colouring or for --only-matching,
+    for example) do not recognize empty strings.
+
+41. Applied a user patch to fix a number of spelling mistakes in comments.
+
+42. Data lines longer than 65536 caused pcretest to crash.
+
+43. Clarified the data type for length and startoffset arguments for pcre_exec
+    and pcre_dfa_exec in the function-specific man pages, where they were
+    explicitly stated to be in bytes, never having been updated. I also added
+    some clarification to the pcreapi man page.
+
+44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
+    a segmentation fault.
+
+
+Version 8.32 30-November-2012
+-----------------------------
+
+1.  Improved JIT compiler optimizations for first character search and single
+    character iterators.
+
+2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
+    Patch by Daniel Richard G.
+
+3.  Single character iterator optimizations in the JIT compiler.
+
+4.  Improved JIT compiler optimizations for character ranges.
+
+5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
+    Reported by Giuseppe D'Angelo.
+
+6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
+    of a line, was being set incorrectly in cases where .* appeared inside
+    atomic brackets at the start of a pattern, or where there was a subsequent
+    *PRUNE or *SKIP.
+
+7.  Improved instruction cache flush for POWER/PowerPC.
+    Patch by Daniel Richard G.
+
+8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
+    grep:
+
+    (a) There is now no limit to the number of patterns to be matched.
+
+    (b) An error is given if a pattern is too long.
+
+    (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
+        are now supported.
+
+    (d) --exclude-from and --include-from (multiple use) have been added.
+
+    (e) Exclusions and inclusions now apply to all files and directories, not
+        just to those obtained from scanning a directory recursively.
+
+    (f) Multiple uses of -f and --file-list are now supported.
+
+    (g) In a Windows environment, the default for -d has been changed from
+        "read" (the GNU grep default) to "skip", because otherwise the presence
+        of a directory in the file list provokes an error.
+
+    (h) The documentation has been revised and clarified in places.
+
+9.  Improve the matching speed of capturing brackets.
+
+10. Changed the meaning of \X so that it now matches a Unicode extended
+    grapheme cluster.
+
+11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
+    out POSIX threads when JIT support is configured.
+
+12. Added support for PCRE_STUDY_EXTRA_NEEDED.
+
+13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
+    structure could go wrong in environments where size_t is not the same size
+    as int.
+
+14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
+    set.
+
+15. The EBCDIC support had decayed; later updates to the code had included
+    explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
+    general tidy up of EBCDIC-related issues, and the documentation was also
+    not quite right. There is now a test that can be run on ASCII systems to
+    check some of the EBCDIC-related things (but is it not a full test).
+
+16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
+    in a small tidy to the code.
+
+17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
+
+18. If the --only-matching (-o) option in pcregrep is specified multiple
+    times, each one causes appropriate output. For example, -o1 -o2 outputs the
+    substrings matched by the 1st and 2nd capturing parentheses. A separating
+    string can be specified by --om-separator (default empty).
+
+19. Improving the first n character searches.
+
+20. Turn case lists for horizontal and vertical white space into macros so that
+    they are defined only once.
+
+21. This set of changes together give more compatible Unicode case-folding
+    behaviour for characters that have more than one other case when UCP
+    support is available.
+
+    (a) The Unicode property table now has offsets into a new table of sets of
+        three or more characters that are case-equivalent. The MultiStage2.py
+        script that generates these tables (the pcre_ucd.c file) now scans
+        CaseFolding.txt instead of UnicodeData.txt for character case
+        information.
+
+    (b) The code for adding characters or ranges of characters to a character
+        class has been abstracted into a generalized function that also handles
+        case-independence. In UTF-mode with UCP support, this uses the new data
+        to handle characters with more than one other case.
+
+    (c) A bug that is fixed as a result of (b) is that codepoints less than 256
+        whose other case is greater than 256 are now correctly matched
+        caselessly. Previously, the high codepoint matched the low one, but not
+        vice versa.
+
+    (d) The processing of \h, \H, \v, and \ in character classes now makes use
+        of the new class addition function, using character lists defined as
+        macros alongside the case definitions of 20 above.
+
+    (e) Caseless back references now work with characters that have more than
+        one other case.
+
+    (f) General caseless matching of characters with more than one other case
+        is supported.
+
+22. Unicode character properties were updated from Unicode 6.2.0
+
+23. Improved CMake support under Windows. Patch by Daniel Richard G.
+
+24. Add support for 32-bit character strings, and UTF-32
+
+25. Major JIT compiler update (code refactoring and bugfixing).
+    Experimental Sparc 32 support is added.
+
+26. Applied a modified version of Daniel Richard G's patch to create
+    pcre.h.generic and config.h.generic by "make" instead of in the
+    PrepareRelease script.
+
+27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
+    pcre_compile.c when checking for a zero character.
+
+28. Introducing a native interface for JIT. Through this interface, the compiled
+    machine code can be directly executed. The purpose of this interface is to
+    provide fast pattern matching, so several sanity checks are not performed.
+    However, feature tests are still performed. The new interface provides
+    1.4x speedup compared to the old one.
+
+29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
+    the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
+    was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
+
+30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
+    greater than 0x7fffffff (which cannot be represented in UTF-8, even under
+    the "old" RFC 2279). Instead, it ended up passing a negative length to
+    pcre_exec().
+
+31. Add support for GCC's visibility feature to hide internal functions.
+
+32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
+    "unknown -C option" after outputting 0 or 1.
+
+33. There is now support for generating a code coverage report for the test
+    suite in environments where gcc is the compiler and lcov is installed. This
+    is mainly for the benefit of the developers.
+
+34. If PCRE is built with --enable-valgrind, certain memory regions are marked
+    unaddressable using valgrind annotations, allowing valgrind to detect
+    invalid memory accesses. This is mainly for the benefit of the developers.
+
+25. (*UTF) can now be used to start a pattern in any of the three libraries.
+
+26. Give configure error if --enable-cpp but no C++ compiler found.
+
+
+Version 8.31 06-July-2012
+-------------------------
+
+1.  Fixing a wrong JIT test case and some compiler warnings.
+
+2.  Removed a bashism from the RunTest script.
+
+3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
+    to unsigned type, result still unsigned" that was given by an MS compiler
+    on encountering the code "-sizeof(xxx)".
+
+4.  Partial matching support is added to the JIT compiler.
+
+5.  Fixed several bugs concerned with partial matching of items that consist
+    of more than one character:
+
+    (a) /^(..)\1/ did not partially match "aba" because checking references was
+        done on an "all or nothing" basis. This also applied to repeated
+        references.
+
+    (b) \R did not give a hard partial match if \r was found at the end of the
+        subject.
+
+    (c) \X did not give a hard partial match after matching one or more
+        characters at the end of the subject.
+
+    (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
+        a partial match for the string "\r".
+
+    (e) When newline was set to CRLF, the metacharacter "." did not recognize
+        a partial match for a CR character at the end of the subject string.
+
+6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
+    running pcretest, the text "(JIT)" added to the output whenever JIT is
+    actually used to run the match.
+
+7.  Individual JIT compile options can be set in pcretest by following -s+[+]
+    or /S+[+] with a digit between 1 and 7.
+
+8.  OP_NOT now supports any UTF character not just single-byte ones.
+
+9.  (*MARK) control verb is now supported by the JIT compiler.
+
+10. The command "./RunTest list" lists the available tests without actually
+    running any of them. (Because I keep forgetting what they all are.)
+
+11. Add PCRE_INFO_MAXLOOKBEHIND.
+
+12. Applied a (slightly modified) user-supplied patch that improves performance
+    when the heap is used for recursion (compiled with --disable-stack-for-
+    recursion). Instead of malloc and free for each heap frame each time a
+    logical recursion happens, frames are retained on a chain and re-used where
+    possible. This sometimes gives as much as 30% improvement.
+
+13. As documented, (*COMMIT) is now confined to within a recursive subpattern
+    call.
+
+14. As documented, (*COMMIT) is now confined to within a positive assertion.
+
+15. It is now possible to link pcretest with libedit as an alternative to
+    libreadline.
+
+16. (*COMMIT) control verb is now supported by the JIT compiler.
+
+17. The Unicode data tables have been updated to Unicode 6.1.0.
+
+18. Added --file-list option to pcregrep.
+
+19. Added binary file support to pcregrep, including the -a, --binary-files,
+    -I, and --text options.
+
+20. The madvise function is renamed for posix_madvise for QNX compatibility
+    reasons. Fixed by Giuseppe D'Angelo.
+
+21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
+
+22. Changed the option for creating symbolic links for 16-bit man pages from
+    -s to -sf so that re-installing does not cause issues.
+
+23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
+
+24. Fixed a very old bug in pcretest that caused errors with restarted DFA
+    matches in certain environments (the workspace was not being correctly
+    retained). Also added to pcre_dfa_exec() a simple plausibility check on
+    some of the workspace data at the beginning of a restart.
+
+25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
+    was not doing so when it should - probably a typo introduced by SVN 528
+    (change 8.10/14).
+
+26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
+    \w+ when the character tables indicated that \x{c4} was a word character.
+    There were several related cases, all because the tests for doing a table
+    lookup were testing for characters less than 127 instead of 255.
+
+27. If a pattern contains capturing parentheses that are not used in a match,
+    their slots in the ovector are set to -1. For those that are higher than
+    any matched groups, this happens at the end of processing. In the case when
+    there were back references that the ovector was too small to contain
+    (causing temporary malloc'd memory to be used during matching), and the
+    highest capturing number was not used, memory off the end of the ovector
+    was incorrectly being set to -1. (It was using the size of the temporary
+    memory instead of the true size.)
+
+28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
+    ovector size, it uses memory at the end of the block that it has got.
+
+29. Check for an overlong MARK name and give an error at compile time. The
+    limit is 255 for the 8-bit library and 65535 for the 16-bit library.
+
+30. JIT compiler update.
+
+31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
+    Rill for the patch.
+
+32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
+
+33. Variable renamings in the PCRE-JIT compiler. No functionality change.
+
+34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
+    SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
+    was enabled.
+
+35. Improve JIT code generation for greedy plus quantifier.
+
+36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
+    1 to "aa" instead of to an empty string. The bug affected repeated groups
+    that could potentially match an empty string.
+
+37. Optimizing single character iterators in JIT.
+
+38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
+    the same checks as \x{...} characters in non-JavaScript mode. Specifically,
+    codepoints that are too big for the mode are faulted, and in a UTF mode,
+    disallowed codepoints are also faulted.
+
+39. If PCRE was compiled with UTF support, in three places in the DFA
+    matcher there was code that should only have been obeyed in UTF mode, but
+    was being obeyed unconditionally. In 8-bit mode this could cause incorrect
+    processing when bytes with values greater than 127 were present. In 16-bit
+    mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
+    both cases the values are those that cannot be the first data item in a UTF
+    character. The three items that might have provoked this were recursions,
+    possessively repeated groups, and atomic groups.
+
+40. Ensure that libpcre is explicitly listed in the link commands for pcretest
+    and pcregrep, because some OS require shared objects to be explicitly
+    passed to ld, causing the link step to fail if they are not.
+
+41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
+    mode, patterns that started with \h* or \R* might be incorrectly matched.
+
+
+Version 8.30 04-February-2012
+-----------------------------
+
+1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
+    name is defined in ctype.h.
+
+2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
+    only in quite long subpatterns.
+
+3.  Removed the function pcre_info(), which has been obsolete and deprecated
+    since it was replaced by pcre_fullinfo() in February 2000.
+
+4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
+    match a (*MARK), and the match failed at the start of the subject, a
+    reference to memory before the start of the subject could occur. This bug
+    was introduced by fix 17 of release 8.21.
+
+5.  A reference to an unset group with zero minimum repetition was giving
+    totally wrong answers (in non-JavaScript-compatibility mode). For example,
+    /(another)?(\1?)test/ matched against "hello world test". This bug was
+    introduced in release 8.13.
+
+6.  Add support for 16-bit character strings (a large amount of work involving
+    many changes and refactorings).
+
+7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
+    command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
+    from a file.
+
+8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
+    rounding is not applied in this particular case).
+
+9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
+    if they appear, or are escaped, in patterns.
+
+10. Get rid of a number of -Wunused-but-set-variable warnings.
+
+11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
+    "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
+    Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
+    also returns the mark "x". This bug applied to capturing parentheses,
+    non-capturing parentheses, and atomic parentheses. It also applied to some
+    assertions.
+
+12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
+    information out of configure.ac instead of relying on pcre.h.generic, which
+    is not stored in the repository.
+
+13. Applied Dmitry V. Levin's patch for a more portable method for linking with
+    -lreadline.
+
+14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
+
+15. Applied Graycode's patch to put the top-level frame on the stack rather
+    than the heap when not using the stack for recursion. This gives a
+    performance improvement in many cases when recursion is not deep.
+
+16. Experimental code added to "pcretest -C" to output the stack frame size.
+
+
+Version 8.21 12-Dec-2011
+------------------------
+
+1.  Updating the JIT compiler.
+
+2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
+    are added as well.
+
+3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
+    PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
+    calling _pcre_jit_exec. Some extra comments are added.
+
+4.  (*MARK) settings inside atomic groups that do not contain any capturing
+    parentheses, for example, (?>a(*:m)), were not being passed out. This bug
+    was introduced by change 18 for 8.20.
+
+5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
+    ECMA-262 standard.
+
+6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
+    erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
+    This bug was probably introduced by change 9 of 8.13.
+
+7.  While fixing 6 above, I noticed that a number of other items were being
+    incorrectly rejected as "not fixed length". This arose partly because newer
+    opcodes had not been added to the fixed-length checking code. I have (a)
+    corrected the bug and added tests for these items, and (b) arranged for an
+    error to occur if an unknown opcode is encountered while checking for fixed
+    length instead of just assuming "not fixed length". The items that were
+    rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
+    (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
+    repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
+
+8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
+    being incorrectly compiled and would have given unpredicatble results.
+
+9.  A possessively repeated subpattern with minimum repeat count greater than
+    one behaved incorrectly. For example, (A){2,}+ behaved as if it was
+    (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
+    the first (A) could occur when it should not.
+
+10. Add a cast and remove a redundant test from the code.
+
+11. JIT should use pcre_malloc/pcre_free for allocation.
+
+12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
+    best practice nowadays, and helps with cross-compiling. (If the exec_prefix
+    is anything other than /usr, -L is still shown).
+
+13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
+
+14. Perl does not support \N without a following name in a [] class; PCRE now
+    also gives an error.
+
+15. If a forward reference was repeated with an upper limit of around 2000,
+    it caused the error "internal error: overran compiling workspace". The
+    maximum number of forward references (including repeats) was limited by the
+    internal workspace, and dependent on the LINK_SIZE. The code has been
+    rewritten so that the workspace expands (via pcre_malloc) if necessary, and
+    the default depends on LINK_SIZE. There is a new upper limit (for safety)
+    of around 200,000 forward references. While doing this, I also speeded up
+    the filling in of repeated forward references.
+
+16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
+    incorrectly expecting the subject to contain another "a" after the start.
+
+17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
+    in the match, the SKIP should be ignored. This was not happening; instead
+    the SKIP was being treated as NOMATCH. For patterns such as
+    /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
+    tested.
+
+18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
+    now much more compatible with Perl, in particular in cases where the result
+    is a non-match for a non-anchored pattern. For example, if
+    /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
+    "m", where previously it did not return a name. A side effect of this
+    change is that for partial matches, the last encountered mark name is
+    returned, as for non matches. A number of tests that were previously not
+    Perl-compatible have been moved into the Perl-compatible test files. The
+    refactoring has had the pleasing side effect of removing one argument from
+    the match() function, thus reducing its stack requirements.
+
+19. If the /S+ option was used in pcretest to study a pattern using JIT,
+    subsequent uses of /S (without +) incorrectly behaved like /S+.
+
+21. Retrieve executable code size support for the JIT compiler and fixing
+    some warnings.
+
+22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
+    not work when the shorter character appeared right at the end of the
+    subject string.
+
+23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
+    systems.
+
+24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
+    output it when the /M option is used in pcretest.
+
+25. The CheckMan script was not being included in the distribution. Also, added
+    an explicit "perl" to run Perl scripts from the PrepareRelease script
+    because this is reportedly needed in Windows.
+
+26. If study data was being save in a file and studying had not found a set of
+    "starts with" bytes for the pattern, the data written to the file (though
+    never used) was taken from uninitialized memory and so caused valgrind to
+    complain.
+
+27. Updated RunTest.bat as provided by Sheri Pierce.
+
+28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
+
+29. Computation of memory usage for the table of capturing group names was
+    giving an unnecessarily large value.
+
+
+Version 8.20 21-Oct-2011
+------------------------
+
+1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
+    a POSIX class. After further experiments with Perl, which convinced me that
+    Perl has bugs and confusions, a closing square bracket is no longer allowed
+    in a POSIX name. This bug also affected patterns with classes that started
+    with full stops.
+
+2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
+    captured substring, but while checking the failing first alternative,
+    substring 1 is temporarily captured. If the output vector supplied to
+    pcre_exec() was not big enough for this capture, the yield of the function
+    was still zero ("insufficient space for captured substrings"). This cannot
+    be totally fixed without adding another stack variable, which seems a lot
+    of expense for a edge case. However, I have improved the situation in cases
+    such as /(a)(b)x|abc/ matched against "abc", where the return code
+    indicates that fewer than the maximum number of slots in the ovector have
+    been set.
+
+3.  Related to (2) above: when there are more back references in a pattern than
+    slots in the output vector, pcre_exec() uses temporary memory during
+    matching, and copies in the captures as far as possible afterwards. It was
+    using the entire output vector, but this conflicts with the specification
+    that only 2/3 is used for passing back captured substrings. Now it uses
+    only the first 2/3, for compatibility. This is, of course, another edge
+    case.
+
+4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
+    main code base, and can be used by building with --enable-jit. When this is
+    done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
+    runtime --no-jit option is given.
+
+5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
+    ovector, the return from the function was zero, implying that there were
+    other matches that did not fit. The correct "exactly full" value is now
+    returned.
+
+6.  If a subpattern that was called recursively or as a subroutine contained
+    (*PRUNE) or any other control that caused it to give a non-standard return,
+    invalid errors such as "Error -26 (nested recursion at the same subject
+    position)" or even infinite loops could occur.
+
+7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
+    computing the minimum length on reaching *ACCEPT, and so ended up with the
+    wrong value of 1 rather than 0. Further investigation indicates that
+    computing a minimum subject length in the presence of *ACCEPT is difficult
+    (think back references, subroutine calls), and so I have changed the code
+    so that no minimum is registered for a pattern that contains *ACCEPT.
+
+8.  If (*THEN) was present in the first (true) branch of a conditional group,
+    it was not handled as intended. [But see 16 below.]
+
+9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
+    Sheri Pierce.
+
+10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
+    the first byte in a match must be "a".
+
+11. Change 17 for 8.13 increased the recursion depth for patterns like
+    /a(?:.)*?a/ drastically. I've improved things by remembering whether a
+    pattern contains any instances of (*THEN). If it does not, the old
+    optimizations are restored. It would be nice to do this on a per-group
+    basis, but at the moment that is not feasible.
+
+12. In some environments, the output of pcretest -C is CRLF terminated. This
+    broke RunTest's code that checks for the link size. A single white space
+    character after the value is now allowed for.
+
+13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
+    For "fr", it uses the Windows-specific input and output files.
+
+14. If (*THEN) appeared in a group that was called recursively or as a
+    subroutine, it did not work as intended. [But see next item.]
+
+15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
+    pattern fragments (but not containing any | characters). If A and B are
+    matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
+    was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
+    D. In other words, Perl considers parentheses that do not contain any |
+    characters to be part of a surrounding alternative, whereas PCRE was
+    treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
+    differently. PCRE now behaves in the same way as Perl, except in the case
+    of subroutine/recursion calls such as (?1) which have in any case always
+    been different (but PCRE had them first :-).
+
+16. Related to 15 above: Perl does not treat the | in a conditional group as
+    creating alternatives. Such a group is treated in the same way as an
+    ordinary group without any | characters when processing (*THEN). PCRE has
+    been changed to match Perl's behaviour.
+
+17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
+    RunGrepTest script failed.
+
+18. Change 22 for version 13 caused atomic groups to use more stack. This is
+    inevitable for groups that contain captures, but it can lead to a lot of
+    stack use in large patterns. The old behaviour has been restored for atomic
+    groups that do not contain any capturing parentheses.
+
+19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
+    suppress the check for a minimum subject length at run time. (If it was
+    given to pcre_exec() or pcre_dfa_exec() it did work.)
+
+20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
+    fail to work when decoding hex characters in data strings in EBCDIC
+    environments.
+
+21. It appears that in at least one Mac OS environment, the isxdigit() function
+    is implemented as a macro that evaluates to its argument more than once,
+    contravening the C 90 Standard (I haven't checked a later standard). There
+    was an instance in pcretest which caused it to go wrong when processing
+    \x{...} escapes in subject strings. The has been rewritten to avoid using
+    things like p++ in the argument of isxdigit().
+
+
+Version 8.13 16-Aug-2011
+------------------------
+
+1.  The Unicode data tables have been updated to Unicode 6.0.0.
+
+2.  Two minor typos in pcre_internal.h have been fixed.
+
+3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
+    pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
+    in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
+
+4.  There were a number of related bugs in the code for matching backrefences
+    caselessly in UTF-8 mode when codes for the characters concerned were
+    different numbers of bytes. For example, U+023A and U+2C65 are an upper
+    and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
+    (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
+    code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
+    2-byte code at the end of the subject (it thought there wasn't enough data
+    left).
+
+5.  Comprehensive information about what went wrong is now returned by
+    pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
+    as the output vector has at least 2 elements. The offset of the start of
+    the failing character and a reason code are placed in the vector.
+
+6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
+    now returned is for the first byte of the failing character, instead of the
+    last byte inspected. This is an incompatible change, but I hope it is small
+    enough not to be a problem. It makes the returned offset consistent with
+    pcre_exec() and pcre_dfa_exec().
+
+7.  pcretest now gives a text phrase as well as the error number when
+    pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
+    failure, the offset and reason code are output.
+
+8.  When \R was used with a maximizing quantifier it failed to skip backwards
+    over a \r\n pair if the subsequent match failed. Instead, it just skipped
+    back over a single character (\n). This seems wrong (because it treated the
+    two characters as a single entity when going forwards), conflicts with the
+    documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
+    behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
+    has been changed.
+
+9.  Some internal refactoring has changed the processing so that the handling
+    of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
+    time (the PCRE_DOTALL option was changed this way some time ago: version
+    7.7 change 16). This has made it possible to abolish the OP_OPT op code,
+    which was always a bit of a fudge. It also means that there is one less
+    argument for the match() function, which reduces its stack requirements
+    slightly. This change also fixes an incompatibility with Perl: the pattern
+    (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
+
+10. More internal refactoring has drastically reduced the number of recursive
+    calls to match() for possessively repeated groups such as (abc)++ when
+    using pcre_exec().
+
+11. While implementing 10, a number of bugs in the handling of groups were
+    discovered and fixed:
+
+    (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
+    (a|)*(?1) gave a compile-time internal error.
+    ((a|)+)+  did not notice that the outer group could match an empty string.
+    (^a|^)+   was not marked as anchored.
+    (.*a|.*)+ was not marked as matching at start or after a newline.
+
+12. Yet more internal refactoring has removed another argument from the match()
+    function. Special calls to this function are now indicated by setting a
+    value in a variable in the "match data" data block.
+
+13. Be more explicit in pcre_study() instead of relying on "default" for
+    opcodes that mean there is no starting character; this means that when new
+    ones are added and accidentally left out of pcre_study(), testing should
+    pick them up.
+
+14. The -s option of pcretest has been documented for ages as being an old
+    synonym of -m (show memory usage). I have changed it to mean "force study
+    for every regex", that is, assume /S for every regex. This is similar to -i
+    and -d etc. It's slightly incompatible, but I'm hoping nobody is still
+    using it. It makes it easier to run collections of tests with and without
+    study enabled, and thereby test pcre_study() more easily. All the standard
+    tests are now run with and without -s (but some patterns can be marked as
+    "never study" - see 20 below).
+
+15. When (*ACCEPT) was used in a subpattern that was called recursively, the
+    restoration of the capturing data to the outer values was not happening
+    correctly.
+
+16. If a recursively called subpattern ended with (*ACCEPT) and matched an
+    empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
+    pattern had matched an empty string, and so incorrectly returned a no
+    match.
+
+17. There was optimizing code for the last branch of non-capturing parentheses,
+    and also for the obeyed branch of a conditional subexpression, which used
+    tail recursion to cut down on stack usage. Unfortunately, now that there is
+    the possibility of (*THEN) occurring in these branches, tail recursion is
+    no longer possible because the return has to be checked for (*THEN). These
+    two optimizations have therefore been removed. [But see 8.20/11 above.]
+
+18. If a pattern containing \R was studied, it was assumed that \R always
+    matched two bytes, thus causing the minimum subject length to be
+    incorrectly computed because \R can also match just one byte.
+
+19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
+    was incorrectly computed.
+
+20. If /S is present twice on a test pattern in pcretest input, it now
+    *disables* studying, thereby overriding the use of -s on the command line
+    (see 14 above). This is necessary for one or two tests to keep the output
+    identical in both cases.
+
+21. When (*ACCEPT) was used in an assertion that matched an empty string and
+    PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
+
+22. When an atomic group that contained a capturing parenthesis was
+    successfully matched, but the branch in which it appeared failed, the
+    capturing was not being forgotten if a higher numbered group was later
+    captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
+    group 1 to "a", when in fact it should be unset. This applied to multi-
+    branched capturing and non-capturing groups, repeated or not, and also to
+    positive assertions (capturing in negative assertions does not happen
+    in PCRE) and also to nested atomic groups.
+
+23. Add the ++ qualifier feature to pcretest, to show the remainder of the
+    subject after a captured substring, to make it easier to tell which of a
+    number of identical substrings has been captured.
+
+24. The way atomic groups are processed by pcre_exec() has been changed so that
+    if they are repeated, backtracking one repetition now resets captured
+    values correctly. For example, if ((?>(a+)b)+aabab) is matched against
+    "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
+    "aaa". Previously, it would have been "a". As part of this code
+    refactoring, the way recursive calls are handled has also been changed.
+
+25. If an assertion condition captured any substrings, they were not passed
+    back unless some other capturing happened later. For example, if
+    (?(?=(a))a) was matched against "a", no capturing was returned.
+
+26. When studying a pattern that contained subroutine calls or assertions,
+    the code for finding the minimum length of a possible match was handling
+    direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
+    group 1 called group 2 while simultaneously a separate group 2 called group
+    1). A stack overflow occurred in this case. I have fixed this by limiting
+    the recursion depth to 10.
+
+27. Updated RunTest.bat in the distribution to the version supplied by Tom
+    Fortmann. This supports explicit test numbers on the command line, and has
+    argument validation and error reporting.
+
+28. An instance of \X with an unlimited repeat could fail if at any point the
+    first character it looked at was a mark character.
+
+29. Some minor code refactoring concerning Unicode properties and scripts
+    should reduce the stack requirement of match() slightly.
+
+30. Added the '=' option to pcretest to check the setting of unused capturing
+    slots at the end of the pattern, which are documented as being -1, but are
+    not included in the return count.
+
+31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
+    compiled something random. Now it gives a compile-time error (as does
+    Perl).
+
+32. A *MARK encountered during the processing of a positive assertion is now
+    recorded and passed back (compatible with Perl).
+
+33. If --only-matching or --colour was set on a pcregrep call whose pattern
+    had alternative anchored branches, the search for a second match in a line
+    was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
+    matched the line "0102" twice. The same bug affected patterns that started
+    with a backwards assertion. For example /\b01|\b02/ also matched "0102"
+    twice.
+
+34. Previously, PCRE did not allow quantification of assertions. However, Perl
+    does, and because of capturing effects, quantifying parenthesized
+    assertions may at times be useful. Quantifiers are now allowed for
+    parenthesized assertions.
+
+35. A minor code tidy in pcre_compile() when checking options for \R usage.
+
+36. \g was being checked for fancy things in a character class, when it should
+    just be a literal "g".
+
+37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
+    appearance of a nested POSIX class supersedes an apparent external class.
+    For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
+    unescaped square brackets may also appear as part of class names. For
+    example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
+    more like Perl. (But see 8.20/1 above.)
+
+38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
+    was because it thought it was \N{name}, which is not supported).
+
+39. Add minix to OS list not supporting the -S option in pcretest.
+
+40. PCRE tries to detect cases of infinite recursion at compile time, but it
+    cannot analyze patterns in sufficient detail to catch mutual recursions
+    such as ((?1))((?2)). There is now a runtime test that gives an error if a
+    subgroup is called recursively as a subpattern for a second time at the
+    same position in the subject string. In previous releases this might have
+    been caught by the recursion limit, or it might have run out of stack.
+
+41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
+    happen only once. PCRE was, however incorrectly giving a compile time error
+    "recursive call could loop indefinitely" because it cannot analyze the
+    pattern in sufficient detail. The compile time test no longer happens when
+    PCRE is compiling a conditional subpattern, but actual runaway loops are
+    now caught at runtime (see 40 above).
+
+42. It seems that Perl allows any characters other than a closing parenthesis
+    to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
+    has been changed to be the same.
+
+43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
+    as not to get warnings when autogen.sh is called. Also changed
+    AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
+
+44. To help people who use pcregrep to scan files containing exceedingly long
+    lines, the following changes have been made:
+
+    (a) The default value of the buffer size parameter has been increased from
+        8K to 20K. (The actual buffer used is three times this size.)
+
+    (b) The default can be changed by ./configure --with-pcregrep-bufsize when
+        PCRE is built.
+
+    (c) A --buffer-size=n option has been added to pcregrep, to allow the size
+        to be set at run time.
+
+    (d) Numerical values in pcregrep options can be followed by K or M, for
+        example --buffer-size=50K.
+
+    (e) If a line being scanned overflows pcregrep's buffer, an error is now
+        given and the return code is set to 2.
+
+45. Add a pointer to the latest mark to the callout data block.
+
+46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
+    partial match of an empty string instead of no match. This was specific to
+    the use of ".".
+
+47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
+    complete match instead of a partial match. This bug was dependent on both
+    the PCRE_UTF8 and PCRE_DOTALL options being set.
+
+48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
+    starting byte set, because \b was not being ignored.
+
+
+Version 8.12 15-Jan-2011
+------------------------
+
+1.  Fixed some typos in the markup of the man pages, and wrote a script that
+    checks for such things as part of the documentation building process.
+
+2.  On a big-endian 64-bit system, pcregrep did not correctly process the
+    --match-limit and --recursion-limit options (added for 8.11). In
+    particular, this made one of the standard tests fail. (The integer value
+    went into the wrong half of a long int.)
+
+3.  If the --colour option was given to pcregrep with -v (invert match), it
+    did strange things, either producing crazy output, or crashing. It should,
+    of course, ignore a request for colour when reporting lines that do not
+    match.
+
+4.  Another pcregrep bug caused similar problems if --colour was specified with
+    -M (multiline) and the pattern match finished with a line ending.
+
+5.  In pcregrep, when a pattern that ended with a literal newline sequence was
+    matched in multiline mode, the following line was shown as part of the
+    match. This seems wrong, so I have changed it.
+
+6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
+    the check for further matches in the same line (so they could be coloured)
+    to overrun the end of the current line. If another match was found, it was
+    incorrectly shown (and then shown again when found in the next line).
+
+7.  If pcregrep was compiled under Windows, there was a reference to the
+    function pcregrep_exit() before it was defined. I am assuming this was
+    the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
+    reported by a user. I've moved the definition above the reference.
+
+
+Version 8.11 10-Dec-2010
+------------------------
+
+1.  (*THEN) was not working properly if there were untried alternatives prior
+    to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
+    backtracked to try for "b" instead of moving to the next alternative branch
+    at the same level (in this case, to look for "c"). The Perl documentation
+    is clear that when (*THEN) is backtracked onto, it goes to the "next
+    alternative in the innermost enclosing group".
+
+2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
+    such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
+    result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
+    (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
+    (*THEN).
+
+3.  If \s appeared in a character class, it removed the VT character from
+    the class, even if it had been included by some previous item, for example
+    in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
+    of \s, but is part of the POSIX "space" class.)
+
+4.  A partial match never returns an empty string (because you can always
+    match an empty string at the end of the subject); however the checking for
+    an empty string was starting at the "start of match" point. This has been
+    changed to the "earliest inspected character" point, because the returned
+    data for a partial match starts at this character. This means that, for
+    example, /(?<=abc)def/ gives a partial match for the subject "abc"
+    (previously it gave "no match").
+
+5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
+    of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
+    previously a full match would be given. However, setting PCRE_PARTIAL_HARD
+    has an implication that the given string is incomplete (because a partial
+    match is preferred over a full match). For this reason, these items now
+    give a partial match in this situation. [Aside: previously, the one case
+    /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
+    match rather than a full match, which was wrong by the old rules, but is
+    now correct.]
+
+6.  There was a bug in the handling of #-introduced comments, recognized when
+    PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
+    If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
+    UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
+    scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
+    but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
+    places in pcre_compile().
+
+7.  Related to (6) above, when pcre_compile() was skipping #-introduced
+    comments when looking ahead for named forward references to subpatterns,
+    the only newline sequence it recognized was NL. It now handles newlines
+    according to the set newline convention.
+
+8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
+    former, but used strtoul(), whereas pcretest avoided strtoul() but did not
+    cater for a lack of strerror(). These oversights have been fixed.
+
+9.  Added --match-limit and --recursion-limit to pcregrep.
+
+10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
+
+11. When the -o option was used, pcregrep was setting a return code of 1, even
+    when matches were found, and --line-buffered was not being honoured.
+
+12. Added an optional parentheses number to the -o and --only-matching options
+    of pcregrep.
+
+13. Imitating Perl's /g action for multiple matches is tricky when the pattern
+    can match an empty string. The code to do it in pcretest and pcredemo
+    needed fixing:
+
+    (a) When the newline convention was "crlf", pcretest got it wrong, skipping
+        only one byte after an empty string match just before CRLF (this case
+        just got forgotten; "any" and "anycrlf" were OK).
+
+    (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
+        mode when an empty string match preceded an ASCII character followed by
+        a non-ASCII character. (The code for advancing by one character rather
+        than one byte was nonsense.)
+
+    (c) The pcredemo.c sample program did not have any code at all to handle
+        the cases when CRLF is a valid newline sequence.
+
+14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
+    as a starting offset was within the subject string. There is now a new
+    error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
+    negative or greater than the length of the string. In order to test this,
+    pcretest is extended to allow the setting of negative starting offsets.
+
+15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
+    starting offset points to the beginning of a UTF-8 character was
+    unnecessarily clumsy. I tidied it up.
+
+16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
+    bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
+
+17. Nobody had reported that the --include_dir option, which was added in
+    release 7.7 should have been called --include-dir (hyphen, not underscore)
+    for compatibility with GNU grep. I have changed it to --include-dir, but
+    left --include_dir as an undocumented synonym, and the same for
+    --exclude-dir, though that is not available in GNU grep, at least as of
+    release 2.5.4.
+
+18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
+    characters from a string of bytes) have been redefined so as not to use
+    loops, in order to improve performance in some environments. At the same
+    time, I abstracted some of the common code into auxiliary macros to save
+    repetition (this should not affect the compiled code).
+
+19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
+    compile-time error is now given if \c is not followed by an ASCII
+    character, that is, a byte less than 128. (In EBCDIC mode, the code is
+    different, and any byte value is allowed.)
+
+20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
+    START_OPTIMIZE option, which is now allowed at compile time - but just
+    passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
+    to pcregrep and other applications that have no direct access to PCRE
+    options. The new /Y option in pcretest sets this option when calling
+    pcre_compile().
+
+21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
+    back references. Groups containing recursive back references were forced to
+    be atomic by that change, but in the case of named groups, the amount of
+    memory required was incorrectly computed, leading to "Failed: internal
+    error: code overflow". This has been fixed.
+
+22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
+    pcretest.c, to avoid build problems in some Borland environments.
+
+
+Version 8.10 25-Jun-2010
+------------------------
+
+1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
+    THEN.
+
+2.  (*ACCEPT) was not working when inside an atomic group.
+
+3.  Inside a character class, \B is treated as a literal by default, but
+    faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
+    causes the error). The code is unchanged, but I tidied the documentation.
+
+4.  Inside a character class, PCRE always treated \R and \X as literals,
+    whereas Perl faults them if its -w option is set. I have changed PCRE so
+    that it faults them when PCRE_EXTRA is set.
+
+5.  Added support for \N, which always matches any character other than
+    newline. (It is the same as "." when PCRE_DOTALL is not set.)
+
+6.  When compiling pcregrep with newer versions of gcc which may have
+    FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
+    declared with attribute warn_unused_result" were given. Just casting the
+    result to (void) does not stop the warnings; a more elaborate fudge is
+    needed. I've used a macro to implement this.
+
+7.  Minor change to pcretest.c to avoid a compiler warning.
+
+8.  Added four artifical Unicode properties to help with an option to make
+    \s etc use properties (see next item). The new properties are: Xan
+    (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
+
+9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
+    use Unicode properties. (*UCP) at the start of a pattern can be used to set
+    this option. Modified pcretest to add /W to test this facility. Added
+    REG_UCP to make it available via the POSIX interface.
+
+10. Added --line-buffered to pcregrep.
+
+11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
+    studied, and the match started with a letter with a code point greater than
+    127 whose first byte was different to the first byte of the other case of
+    the letter, the other case of this starting letter was not recognized
+    (#976).
+
+12. If a pattern that was studied started with a repeated Unicode property
+    test, for example, \p{Nd}+, there was the theoretical possibility of
+    setting up an incorrect bitmap of starting bytes, but fortunately it could
+    not have actually happened in practice until change 8 above was made (it
+    added property types that matched character-matching opcodes).
+
+13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
+    possible starting bytes for non-anchored patterns.
+
+14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
+    \R, and also a number of cases that involve Unicode properties, both
+    explicit and implicit when PCRE_UCP is set.
+
+15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
+    input, it could crash or give wrong results if characters with values
+    greater than 0xc0 were present in the subject string. (Detail: it assumed
+    UTF-8 input when processing these items.)
+
+16. Added a lot of (int) casts to avoid compiler warnings in systems where
+    size_t is 64-bit (#991).
+
+17. Added a check for running out of memory when PCRE is compiled with
+    --disable-stack-for-recursion (#990).
+
+18. If the last data line in a file for pcretest does not have a newline on
+    the end, a newline was missing in the output.
+
+19. The default pcre_chartables.c file recognizes only ASCII characters (values
+    less than 128) in its various bitmaps. However, there is a facility for
+    generating tables according to the current locale when PCRE is compiled. It
+    turns out that in some environments, 0x85 and 0xa0, which are Unicode space
+    characters, are recognized by isspace() and therefore were getting set in
+    these tables, and indeed these tables seem to approximate to ISO 8859. This
+    caused a problem in UTF-8 mode when pcre_study() was used to create a list
+    of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
+    which of course cannot start UTF-8 characters. I have changed the code so
+    that only real ASCII characters (less than 128) and the correct starting
+    bytes for UTF-8 encodings are set for characters greater than 127 when in
+    UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
+    altogether.)
+
+20. Added the /T option to pcretest so as to be able to run tests with non-
+    standard character tables, thus making it possible to include the tests
+    used for 19 above in the standard set of tests.
+
+21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
+    reference to a subpattern the other side of a comment that contains an
+    opening parenthesis caused either an internal compiling error, or a
+    reference to the wrong subpattern.
+
+
+Version 8.02 19-Mar-2010
+------------------------
+
+1.  The Unicode data tables have been updated to Unicode 5.2.0.
+
+2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
+    configured.
+
+3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
+    original author of that file, following a query about its status.
+
+4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
+    inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
+
+5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
+    quantifier applied to a forward-referencing subroutine call, could compile
+    incorrect code or give the error "internal error: previously-checked
+    referenced subpattern not found".
+
+6.  Both MS Visual Studio and Symbian OS have problems with initializing
+    variables to point to external functions. For these systems, therefore,
+    pcre_malloc etc. are now initialized to local functions that call the
+    relevant global functions.
+
+7.  There were two entries missing in the vectors called coptable and poptable
+    in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
+    I've fixed the data, and added a kludgy way of testing at compile time that
+    the lengths are correct (equal to the number of opcodes).
+
+8.  Following on from 7, I added a similar kludge to check the length of the
+    eint vector in pcreposix.c.
+
+9.  Error texts for pcre_compile() are held as one long string to avoid too
+    much relocation at load time. To find a text, the string is searched,
+    counting zeros. There was no check for running off the end of the string,
+    which could happen if a new error number was added without updating the
+    string.
+
+10. \K gave a compile-time error if it appeared in a lookbehind assersion.
+
+11. \K was not working if it appeared in an atomic group or in a group that
+    was called as a "subroutine", or in an assertion. Perl 5.11 documents that
+    \K is "not well defined" if used in an assertion. PCRE now accepts it if
+    the assertion is positive, but not if it is negative.
+
+12. Change 11 fortuitously reduced the size of the stack frame used in the
+    "match()" function of pcre_exec.c by one pointer. Forthcoming
+    implementation of support for (*MARK) will need an extra pointer on the
+    stack; I have reserved it now, so that the stack frame size does not
+    decrease.
+
+13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
+    item in branch that calls a recursion is a subroutine call - as in the
+    second branch in the above example - was incorrectly given the compile-
+    time error "recursive call could loop indefinitely" because pcre_compile()
+    was not correctly checking the subroutine for matching a non-empty string.
+
+14. The checks for overrunning compiling workspace could trigger after an
+    overrun had occurred. This is a "should never occur" error, but it can be
+    triggered by pathological patterns such as hundreds of nested parentheses.
+    The checks now trigger 100 bytes before the end of the workspace.
+
+15. Fix typo in configure.ac: "srtoq" should be "strtoq".
+
+
+Version 8.01 19-Jan-2010
+------------------------
+
+1.  If a pattern contained a conditional subpattern with only one branch (in
+    particular, this includes all (*DEFINE) patterns), a call to pcre_study()
+    computed the wrong minimum data length (which is of course zero for such
+    subpatterns). This could cause incorrect "no match" results.
+
+2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
+    the pattern is reset in the first branch, pcre_compile() failed with
+    "internal error: code overflow at offset...". This happened only when
+    the reset was to the original external option setting. (An optimization
+    abstracts leading options settings into an external setting, which was the
+    cause of this.)
+
+3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
+    of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
+    assertion pattern did not match (meaning that the assertion was true), it
+    was incorrectly treated as false if the SKIP had been reached during the
+    matching. This also applied to assertions used as conditions.
+
+4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
+    assertion subpattern, including such a pattern used as a condition,
+    unpredictable results occurred, instead of the error return
+    PCRE_ERROR_DFA_UITEM.
+
+5.  The C++ GlobalReplace function was not working like Perl for the special
+    situation when an empty string is matched. It now does the fancy magic
+    stuff that is necessary.
+
+6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
+    removed. (These were left over from very, very early versions of PCRE.)
+
+7.  Some cosmetic changes to the code to make life easier when compiling it
+    as part of something else:
+
+    (a) Change DEBUG to PCRE_DEBUG.
+
+    (b) In pcre_compile(), rename the member of the "branch_chain" structure
+        called "current" as "current_branch", to prevent a collision with the
+        Linux macro when compiled as a kernel module.
+
+    (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
+        prevent a collision with the Linux macro when compiled as a kernel
+        module.
+
+8.  In pcre_compile() there are some checks for integer overflows that used to
+    cast potentially large values to (double). This has been changed to that
+    when building, a check for int64_t is made, and if it is found, it is used
+    instead, thus avoiding the use of floating point arithmetic. (There is no
+    other use of FP in PCRE.) If int64_t is not found, the fallback is to
+    double.
+
+9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
+    2005 (difference between two addresses compared to an unsigned value).
+
+10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
+    custom one, because of the following reported problem in Windows:
+
+      - libbz2 uses the Pascal calling convention (WINAPI) for the functions
+          under Win32.
+      - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
+          therefore missing the function definition.
+      - The compiler thus generates a "C" signature for the test function.
+      - The linker fails to find the "C" function.
+      - PCRE fails to configure if asked to do so against libbz2.
+
+11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
+    messages were output:
+
+      Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
+      rerunning libtoolize, to keep the correct libtool macros in-tree.
+      Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
+
+    I have done both of these things.
+
+12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
+    most of the time, it *can* run out if it is given a pattern that contains a
+    runaway infinite recursion. I updated the discussion in the pcrestack man
+    page.
+
+13. Now that we have gone to the x.xx style of version numbers, the minor
+    version may start with zero. Using 08 or 09 is a bad idea because users
+    might check the value of PCRE_MINOR in their code, and 08 or 09 may be
+    interpreted as invalid octal numbers. I've updated the previous comment in
+    configure.ac, and also added a check that gives an error if 08 or 09 are
+    used.
+
+14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
+    causing partial matching to fail when the end of the subject matched \W
+    in a UTF-8 pattern where \W was quantified with a minimum of 3.
+
+15. There were some discrepancies between the declarations in pcre_internal.h
+    of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
+    their definitions. The declarations used "const uschar *" and the
+    definitions used USPTR. Even though USPTR is normally defined as "const
+    unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
+    reported that: "This difference in casting confuses some C++ compilers, for
+    example, SunCC recognizes above declarations as different functions and
+    generates broken code for hbpcre." I have changed the declarations to use
+    USPTR.
+
+16. GNU libtool is named differently on some systems. The autogen.sh script now
+    tries several variants such as glibtoolize (MacOSX) and libtoolize1x
+    (FreeBSD).
+
+17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
+    (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
+    comment: "Figure out how to create a longlong from a string: strtoll and
+    equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
+    instance, but it only takes 2 args instead of 3!"
+
+18. A subtle bug concerned with back references has been fixed by a change of
+    specification, with a corresponding code fix. A pattern such as
+    ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
+    refers, was giving matches when it shouldn't. For example, xa=xaaa would
+    match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
+    same bug. Such groups have to be quantified to be useful, or contained
+    inside another quantified group. (If there's no repetition, the reference
+    can never match.) The problem arises because, having left the group and
+    moved on to the rest of the pattern, a later failure that backtracks into
+    the group uses the captured value from the final iteration of the group
+    rather than the correct earlier one. I have fixed this in PCRE by forcing
+    any group that contains a reference to itself to be an atomic group; that
+    is, there cannot be any backtracking into it once it has completed. This is
+    similar to recursive and subroutine calls.
+
+
+Version 8.00 19-Oct-09
+----------------------
+
+1.  The table for translating pcre_compile() error codes into POSIX error codes
+    was out-of-date, and there was no check on the pcre_compile() error code
+    being within the table. This could lead to an OK return being given in
+    error.
+
+2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
+    "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
+    in a Windows environment.
+
+3.  The pcregrep --count option prints the count for each file even when it is
+    zero, as does GNU grep. However, pcregrep was also printing all files when
+    --files-with-matches was added. Now, when both options are given, it prints
+    counts only for those files that have at least one match. (GNU grep just
+    prints the file name in this circumstance, but including the count seems
+    more useful - otherwise, why use --count?) Also ensured that the
+    combination -clh just lists non-zero counts, with no names.
+
+4.  The long form of the pcregrep -F option was incorrectly implemented as
+    --fixed_strings instead of --fixed-strings. This is an incompatible change,
+    but it seems right to fix it, and I didn't think it was worth preserving
+    the old behaviour.
+
+5.  The command line items --regex=pattern and --regexp=pattern were not
+    recognized by pcregrep, which required --regex pattern or --regexp pattern
+    (with a space rather than an '='). The man page documented the '=' forms,
+    which are compatible with GNU grep; these now work.
+
+6.  No libpcreposix.pc file was created for pkg-config; there was just
+    libpcre.pc and libpcrecpp.pc. The omission has been rectified.
+
+7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
+    when UCP support is not needed, by modifying the Python script that
+    generates it from Unicode data files. This should not matter if the module
+    is correctly used as a library, but I received one complaint about 50K of
+    unwanted data. My guess is that the person linked everything into his
+    program rather than using a library. Anyway, it does no harm.
+
+8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
+    was a minimum greater than 1 for a wide character in a possessive
+    repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
+    which had an unlimited repeat of a nested, fixed maximum repeat of a wide
+    character. Chaos in the form of incorrect output or a compiling loop could
+    result.
+
+9.  The restrictions on what a pattern can contain when partial matching is
+    requested for pcre_exec() have been removed. All patterns can now be
+    partially matched by this function. In addition, if there are at least two
+    slots in the offset vector, the offset of the earliest inspected character
+    for the match and the offset of the end of the subject are set in them when
+    PCRE_ERROR_PARTIAL is returned.
+
+10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
+    synonymous with PCRE_PARTIAL, for backwards compatibility, and
+    PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
+    and may be more useful for multi-segment matching.
+
+11. Partial matching with pcre_exec() is now more intuitive. A partial match
+    used to be given if ever the end of the subject was reached; now it is
+    given only if matching could not proceed because another character was
+    needed. This makes a difference in some odd cases such as Z(*FAIL) with the
+    string "Z", which now yields "no match" instead of "partial match". In the
+    case of pcre_dfa_exec(), "no match" is given if every matching path for the
+    final character ended with (*FAIL).
+
+12. Restarting a match using pcre_dfa_exec() after a partial match did not work
+    if the pattern had a "must contain" character that was already found in the
+    earlier partial match, unless partial matching was again requested. For
+    example, with the pattern /dog.(body)?/, the "must contain" character is
+    "g". If the first part-match was for the string "dog", restarting with
+    "sbody" failed. This bug has been fixed.
+
+13. The string returned by pcre_dfa_exec() after a partial match has been
+    changed so that it starts at the first inspected character rather than the
+    first character of the match. This makes a difference only if the pattern
+    starts with a lookbehind assertion or \b or \B (\K is not supported by
+    pcre_dfa_exec()). It's an incompatible change, but it makes the two
+    matching functions compatible, and I think it's the right thing to do.
+
+14. Added a pcredemo man page, created automatically from the pcredemo.c file,
+    so that the demonstration program is easily available in environments where
+    PCRE has not been installed from source.
+
+15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
+    libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
+    library.
+
+16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
+    It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
+    is not the first non-POSIX option to be added. Clearly some people find
+    these options useful.
+
+17. If a caller to the POSIX matching function regexec() passes a non-zero
+    value for nmatch with a NULL value for pmatch, the value of
+    nmatch is forced to zero.
+
+18. RunGrepTest did not have a test for the availability of the -u option of
+    the diff command, as RunTest does. It now checks in the same way as
+    RunTest, and also checks for the -b option.
+
+19. If an odd number of negated classes containing just a single character
+    interposed, within parentheses, between a forward reference to a named
+    subpattern and the definition of the subpattern, compilation crashed with
+    an internal error, complaining that it could not find the referenced
+    subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
+    [The bug was that it was starting one character too far in when skipping
+    over the character class, thus treating the ] as data rather than
+    terminating the class. This meant it could skip too much.]
+
+20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
+    /g option in pcretest when the pattern contains \K, which makes it possible
+    to have an empty string match not at the start, even when the pattern is
+    anchored. Updated pcretest and pcredemo to use this option.
+
+21. If the maximum number of capturing subpatterns in a recursion was greater
+    than the maximum at the outer level, the higher number was returned, but
+    with unset values at the outer level. The correct (outer level) value is
+    now given.
+
+22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
+    PCRE did not set those parentheses (unlike Perl). I have now found a way to
+    make it do so. The string so far is captured, making this feature
+    compatible with Perl.
+
+23. The tests have been re-organized, adding tests 11 and 12, to make it
+    possible to check the Perl 5.10 features against Perl 5.10.
+
+24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
+    pattern matches a fixed length string. PCRE did not allow this; now it
+    does. Neither allows recursion.
+
+25. I finally figured out how to implement a request to provide the minimum
+    length of subject string that was needed in order to match a given pattern.
+    (It was back references and recursion that I had previously got hung up
+    on.) This code has now been added to pcre_study(); it finds a lower bound
+    to the length of subject needed. It is not necessarily the greatest lower
+    bound, but using it to avoid searching strings that are too short does give
+    some useful speed-ups. The value is available to calling programs via
+    pcre_fullinfo().
+
+26. While implementing 25, I discovered to my embarrassment that pcretest had
+    not been passing the result of pcre_study() to pcre_dfa_exec(), so the
+    study optimizations had never been tested with that matching function.
+    Oops. What is worse, even when it was passed study data, there was a bug in
+    pcre_dfa_exec() that meant it never actually used it. Double oops. There
+    were also very few tests of studied patterns with pcre_dfa_exec().
+
+27. If (?| is used to create subpatterns with duplicate numbers, they are now
+    allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
+    on the other side of the coin, they are no longer allowed to have different
+    names, because these cannot be distinguished in PCRE, and this has caused
+    confusion. (This is a difference from Perl.)
+
+28. When duplicate subpattern names are present (necessarily with different
+    numbers, as required by 27 above), and a test is made by name in a
+    conditional pattern, either for a subpattern having been matched, or for
+    recursion in such a pattern, all the associated numbered subpatterns are
+    tested, and the overall condition is true if the condition is true for any
+    one of them. This is the way Perl works, and is also more like the way
+    testing by number works.
+
+
+Version 7.9 11-Apr-09
+---------------------
+
+1.  When building with support for bzlib/zlib (pcregrep) and/or readline
+    (pcretest), all targets were linked against these libraries. This included
+    libpcre, libpcreposix, and libpcrecpp, even though they do not use these
+    libraries. This caused unwanted dependencies to be created. This problem
+    has been fixed, and now only pcregrep is linked with bzlib/zlib and only
+    pcretest is linked with readline.
+
+2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
+    "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
+    moved outside it again, because FALSE and TRUE are already defined in AIX,
+    but BOOL is not.
+
+3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
+    PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
+
+4.  The pcregrep documentation said spaces were inserted as well as colons (or
+    hyphens) following file names and line numbers when outputting matching
+    lines. This is not true; no spaces are inserted. I have also clarified the
+    wording for the --colour (or --color) option.
+
+5.  In pcregrep, when --colour was used with -o, the list of matching strings
+    was not coloured; this is different to GNU grep, so I have changed it to be
+    the same.
+
+6.  When --colo(u)r was used in pcregrep, only the first matching substring in
+    each matching line was coloured. Now it goes on to look for further matches
+    of any of the test patterns, which is the same behaviour as GNU grep.
+
+7.  A pattern that could match an empty string could cause pcregrep to loop; it
+    doesn't make sense to accept an empty string match in pcregrep, so I have
+    locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
+    seems to be how GNU grep behaves. [But see later change 40 for release
+    8.33.]
+
+8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
+    start or after a newline", because the conditional assertion was not being
+    correctly handled. The rule now is that both the assertion and what follows
+    in the first alternative must satisfy the test.
+
+9.  If auto-callout was enabled in a pattern with a conditional group whose
+    condition was an assertion, PCRE could crash during matching, both with
+    pcre_exec() and pcre_dfa_exec().
+
+10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
+    used for matching.
+
+11. Unicode property support in character classes was not working for
+    characters (bytes) greater than 127 when not in UTF-8 mode.
+
+12. Added the -M command line option to pcretest.
+
+14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
+
+15. Added the PCRE_NO_START_OPTIMIZE match-time option.
+
+16. Added comments and documentation about mis-use of no_arg in the C++
+    wrapper.
+
+17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
+    from Martin Jerabek that uses macro names for all relevant character and
+    string constants.
+
+18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
+    SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
+    SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
+    these, but not everybody uses configure.
+
+19. A conditional group that had only one branch was not being correctly
+    recognized as an item that could match an empty string. This meant that an
+    enclosing group might also not be so recognized, causing infinite looping
+    (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
+    with the subject "ab", where knowledge that the repeated group can match
+    nothing is needed in order to break the loop.
+
+20. If a pattern that was compiled with callouts was matched using pcre_dfa_
+    exec(), but without supplying a callout function, matching went wrong.
+
+21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
+    leak if the size of the offset vector was greater than 30. When the vector
+    is smaller, the saved offsets during recursion go onto a local stack
+    vector, but for larger vectors malloc() is used. It was failing to free
+    when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
+    error, in fact).
+
+22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
+    heapframe that is used only when UTF-8 support is enabled. This caused no
+    problem, but was untidy.
+
+23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
+    CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
+    included within another project.
+
+24. Steven Van Ingelgem's patches to add more options to the CMake support,
+    slightly modified by me:
+
+      (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
+          not building pcregrep.
+
+      (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
+          if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
+
+25. Forward references, both numeric and by name, in patterns that made use of
+    duplicate group numbers, could behave incorrectly or give incorrect errors,
+    because when scanning forward to find the reference group, PCRE was not
+    taking into account the duplicate group numbers. A pattern such as
+    ^X(?3)(a)(?|(b)|(q))(Y) is an example.
+
+26. Changed a few more instances of "const unsigned char *" to USPTR, making
+    the feature of a custom pointer more persuasive (as requested by a user).
+
+27. Wrapped the definitions of fileno and isatty for Windows, which appear in
+    pcretest.c, inside #ifndefs, because it seems they are sometimes already
+    pre-defined.
+
+28. Added support for (*UTF8) at the start of a pattern.
+
+29. Arrange for flags added by the "release type" setting in CMake to be shown
+    in the configuration summary.
+
+
+Version 7.8 05-Sep-08
+---------------------
+
+1.  Replaced UCP searching code with optimized version as implemented for Ad
+    Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
+    stage table and inline lookup instead of a function, giving speed ups of 2
+    to 5 times on some simple patterns that I tested. Permission was given to
+    distribute the MultiStage2.py script that generates the tables (it's not in
+    the tarball, but is in the Subversion repository).
+
+2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
+    scripts.
+
+3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
+    a group with a zero qualifier. The result of the study could be incorrect,
+    or the function might crash, depending on the pattern.
+
+4.  Caseless matching was not working for non-ASCII characters in back
+    references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
+    It now works when Unicode Property Support is available.
+
+5.  In pcretest, an escape such as \x{de} in the data was always generating
+    a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
+    non-UTF-8 mode. If the value is greater than 255, it gives a warning about
+    truncation.
+
+6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
+
+7.  Added two (int) casts to pcregrep when printing the difference of two
+    pointers, in case they are 64-bit values.
+
+8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
+    test 2 if it fails.
+
+9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
+    and a #define of that name to empty if it is not externally set. This is to
+    allow users of MSVC to set it if necessary.
+
+10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
+    the convenience functions in the pcre_get.c source file.
+
+11. An option change at the start of a pattern that had top-level alternatives
+    could cause overwriting and/or a crash. This command provoked a crash in
+    some environments:
+
+      printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
+
+    This potential security problem was recorded as CVE-2008-2371.
+
+12. For a pattern where the match had to start at the beginning or immediately
+    after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
+    pcre_dfa_exec() could read past the end of the passed subject if there was
+    no match. To help with detecting such bugs (e.g. with valgrind), I modified
+    pcretest so that it places the subject at the end of its malloc-ed buffer.
+
+13. The change to pcretest in 12 above threw up a couple more cases when pcre_
+    exec() might read past the end of the data buffer in UTF-8 mode.
+
+14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
+    the data contained the byte 0x85 as part of a UTF-8 character within its
+    first line. This applied both to normal and DFA matching.
+
+15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
+    /^[^d]*?$/8 failed to match "abc".
+
+16. Added a missing copyright notice to pcrecpp_internal.h.
+
+17. Make it more clear in the documentation that values returned from
+    pcre_exec() in ovector are byte offsets, not character counts.
+
+18. Tidied a few places to stop certain compilers from issuing warnings.
+
+19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
+    supplied by Stefan Weber. I made a further small update for 7.8 because
+    there is a change of source arrangements: the pcre_searchfuncs.c module is
+    replaced by pcre_ucd.c.
+
+
+Version 7.7 07-May-08
+---------------------
+
+1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
+    a string to a long long, pretend we don't even have a long long." This is
+    done by checking for the strtoq, strtoll, and _strtoi64 functions.
+
+2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
+    pre-7.6 versions, which defined a global no_arg variable instead of putting
+    it in the RE class. (See also #8 below.)
+
+3.  Remove a line of dead code, identified by coverity and reported by Nuno
+    Lopes.
+
+4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
+
+    (1) The include/exclude patterns were being applied to the whole pathnames
+        of files, instead of just to the final components.
+
+    (2) If there was more than one level of directory, the subdirectories were
+        skipped unless they satisfied the include/exclude conditions. This is
+        inconsistent with GNU grep (and could even be seen as contrary to the
+        pcregrep specification - which I improved to make it absolutely clear).
+        The action now is always to scan all levels of directory, and just
+        apply the include/exclude patterns to regular files.
+
+5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
+    --exclude_dir in the tests to avoid scanning .svn directories.
+
+6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
+    NUL character as backslash + 0 rather than backslash + NUL, because PCRE
+    doesn't support NULs in patterns.
+
+7.  Added some missing "const"s to declarations of static tables in
+    pcre_compile.c and pcre_dfa_exec.c.
+
+8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
+    caused by fix #2  above. (Subsequently also a second patch to fix the
+    first patch. And a third patch - this was a messy problem.)
+
+9.  Applied Craig's patch to remove the use of push_back().
+
+10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
+    matching function regexec().
+
+11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
+    which, however, unlike Perl's \g{...}, are subroutine calls, not back
+    references. PCRE supports relative numbers with this syntax (I don't think
+    Oniguruma does).
+
+12. Previously, a group with a zero repeat such as (...){0} was completely
+    omitted from the compiled regex. However, this means that if the group
+    was called as a subroutine from elsewhere in the pattern, things went wrong
+    (an internal error was given). Such groups are now left in the compiled
+    pattern, with a new opcode that causes them to be skipped at execution
+    time.
+
+13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
+    to the way PCRE behaves:
+
+    (a) A lone ] character is dis-allowed (Perl treats it as data).
+
+    (b) A back reference to an unmatched subpattern matches an empty string
+        (Perl fails the current match path).
+
+    (c) A data ] in a character class must be notated as \] because if the
+        first data character in a class is ], it defines an empty class. (In
+        Perl it is not possible to have an empty class.) The empty class []
+        never matches; it forces failure and is equivalent to (*FAIL) or (?!).
+        The negative empty class [^] matches any one character, independently
+        of the DOTALL setting.
+
+14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
+    non-existent subpattern following a character class starting with ']' and
+    containing () gave an internal compiling error instead of "reference to
+    non-existent subpattern". Fortunately, when the pattern did exist, the
+    compiled code was correct. (When scanning forwards to check for the
+    existence of the subpattern, it was treating the data ']' as terminating
+    the class, so got the count wrong. When actually compiling, the reference
+    was subsequently set up correctly.)
+
+15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
+    it was being rejected as not supported by pcre_dfa_exec(), even though
+    other assertions are supported. I have made pcre_dfa_exec() support
+    (*FAIL).
+
+16. The implementation of 13c above involved the invention of a new opcode,
+    OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
+    cannot be changed at match time, I realized I could make a small
+    improvement to matching performance by compiling OP_ALLANY instead of
+    OP_ANY for "." when DOTALL was set, and then removing the runtime tests
+    on the OP_ANY path.
+
+17. Compiling pcretest on Windows with readline support failed without the
+    following two fixes: (1) Make the unistd.h include conditional on
+    HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
+
+18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
+    ncurses library to be included for pcretest when ReadLine support is
+    requested, but also to allow for it to be overridden. This patch came from
+    Daniel Bergström.
+
+19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
+    as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
+    any errors with the current Unicode tables. Thanks to Peter Kankowski for
+    spotting this.
+
+
+Version 7.6 28-Jan-08
+---------------------
+
+1.  A character class containing a very large number of characters with
+    codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
+    overflow.
+
+2.  Patch to cut out the "long long" test in pcrecpp_unittest when
+    HAVE_LONG_LONG is not defined.
+
+3.  Applied Christian Ehrlicher's patch to update the CMake build files to
+    bring them up to date and include new features. This patch includes:
+
+    - Fixed PH's badly added libz and libbz2 support.
+    - Fixed a problem with static linking.
+    - Added pcredemo. [But later removed - see 7 below.]
+    - Fixed dftables problem and added an option.
+    - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
+        HAVE_LONG_LONG.
+    - Added readline support for pcretest.
+    - Added an listing of the option settings after cmake has run.
+
+4.  A user submitted a patch to Makefile that makes it easy to create
+    "pcre.dll" under mingw when using Configure/Make. I added stuff to
+    Makefile.am that cause it to include this special target, without
+    affecting anything else. Note that the same mingw target plus all
+    the other distribution libraries and programs are now supported
+    when configuring with CMake (see 6 below) instead of with
+    Configure/Make.
+
+5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
+    This is an attempt to solve the reported problem "pcrecpp::no_arg is not
+    exported in the Windows port". It has not yet been confirmed that the patch
+    solves the problem, but it does no harm.
+
+6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
+    NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
+    with CMake, and also correct the comment about stack recursion.
+
+7.  Remove the automatic building of pcredemo from the ./configure system and
+    from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
+    of a program that users should build themselves after PCRE is installed, so
+    building it automatically is not really right. What is more, it gave
+    trouble in some build environments.
+
+8.  Further tidies to CMakeLists.txt from Sheri and Christian.
+
+
+Version 7.5 10-Jan-08
+---------------------
+
+1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
+    values in parens when parsing an RE using the C++ wrapper."
+
+2.  Negative specials like \S did not work in character classes in UTF-8 mode.
+    Characters greater than 255 were excluded from the class instead of being
+    included.
+
+3.  The same bug as (2) above applied to negated POSIX classes such as
+    [:^space:].
+
+4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
+    defined or documented. It seems to have been a typo for PCRE_STATIC, so
+    I have changed it.
+
+5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
+    first named subpattern) and a construct such as (?&a) would reference the
+    first named subpattern whose name started with "a" (in other words, the
+    length check was missing). Both these problems are fixed. "Subpattern name
+    expected" is now given for (?&) (a zero-length name), and this patch also
+    makes it give the same error for \k'' (previously it complained that that
+    was a reference to a non-existent subpattern).
+
+6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
+    this is right because (?- can be followed by option settings as well as by
+    digits. I have, however, made the messages clearer.
+
+7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
+    than the number used in the conditional) now cause a compile-time error.
+    This is actually not compatible with Perl, which accepts such patterns, but
+    treats the conditional as always being FALSE (as PCRE used to), but it
+    seems to me that giving a diagnostic is better.
+
+8.  Change "alphameric" to the more common word "alphanumeric" in comments
+    and messages.
+
+9.  Fix two occurrences of "backslash" in comments that should have been
+    "backspace".
+
+10. Remove two redundant lines of code that can never be obeyed (their function
+    was moved elsewhere).
+
+11. The program that makes PCRE's Unicode character property table had a bug
+    which caused it to generate incorrect table entries for sequences of
+    characters that have the same character type, but are in different scripts.
+    It amalgamated them into a single range, with the script of the first of
+    them. In other words, some characters were in the wrong script. There were
+    thirteen such cases, affecting characters in the following ranges:
+
+      U+002b0 - U+002c1
+      U+0060c - U+0060d
+      U+0061e - U+00612
+      U+0064b - U+0065e
+      U+0074d - U+0076d
+      U+01800 - U+01805
+      U+01d00 - U+01d77
+      U+01d9b - U+01dbf
+      U+0200b - U+0200f
+      U+030fc - U+030fe
+      U+03260 - U+0327f
+      U+0fb46 - U+0fbb1
+      U+10450 - U+1049d
+
+12. The -o option (show only the matching part of a line) for pcregrep was not
+    compatible with GNU grep in that, if there was more than one match in a
+    line, it showed only the first of them. It now behaves in the same way as
+    GNU grep.
+
+13. If the -o and -v options were combined for pcregrep, it printed a blank
+    line for every non-matching line. GNU grep prints nothing, and pcregrep now
+    does the same. The return code can be used to tell if there were any
+    non-matching lines.
+
+14. Added --file-offsets and --line-offsets to pcregrep.
+
+15. The pattern (?=something)(?R) was not being diagnosed as a potentially
+    infinitely looping recursion. The bug was that positive lookaheads were not
+    being skipped when checking for a possible empty match (negative lookaheads
+    and both kinds of lookbehind were skipped).
+
+16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
+    inclusion of <windows.h> to before rather than after the definition of
+    INVALID_FILE_ATTRIBUTES (patch from David Byron).
+
+17. Specifying a possessive quantifier with a specific limit for a Unicode
+    character property caused pcre_compile() to compile bad code, which led at
+    runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
+    are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
+    caused the error; without that there was no problem.
+
+18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
+
+19. Added --enable-pcretest-libreadline.
+
+20. In pcrecpp.cc, the variable 'count' was incremented twice in
+    RE::GlobalReplace(). As a result, the number of replacements returned was
+    double what it should be. I removed one of the increments, but Craig sent a
+    later patch that removed the other one (the right fix) and added unit tests
+    that check the return values (which was not done before).
+
+21. Several CMake things:
+
+    (1) Arranged that, when cmake is used on Unix, the libraries end up with
+        the names libpcre and libpcreposix, not just pcre and pcreposix.
+
+    (2) The above change means that pcretest and pcregrep are now correctly
+        linked with the newly-built libraries, not previously installed ones.
+
+    (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
+
+22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
+    crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
+    UTF-8 newline character). The key issue is that the pattern starts .*;
+    this means that the match must be either at the beginning, or after a
+    newline. The bug was in the code for advancing after a failed match and
+    checking that the new position followed a newline. It was not taking
+    account of UTF-8 characters correctly.
+
+23. PCRE was behaving differently from Perl in the way it recognized POSIX
+    character classes. PCRE was not treating the sequence [:...:] as a
+    character class unless the ... were all letters. Perl, however, seems to
+    allow any characters between [: and :], though of course it rejects as
+    unknown any "names" that contain non-letters, because all the known class
+    names consist only of letters. Thus, Perl gives an error for [[:1234:]],
+    for example, whereas PCRE did not - it did not recognize a POSIX character
+    class. This seemed a bit dangerous, so the code has been changed to be
+    closer to Perl. The behaviour is not identical to Perl, because PCRE will
+    diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
+    treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
+    Perl does, and where it didn't before.
+
+24. Rewrite so as to remove the single use of %n from pcregrep because in some
+    Windows environments %n is disabled by default.
+
+
+Version 7.4 21-Sep-07
+---------------------
+
+1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
+    means that a class such as [\s] counted as "explicit reference to CR or
+    LF". That isn't really right - the whole point of the change was to try to
+    help when there was an actual mention of one of the two characters. So now
+    the change happens only if \r or \n (or a literal CR or LF) character is
+    encountered.
+
+2.  The 32-bit options word was also used for 6 internal flags, but the numbers
+    of both had grown to the point where there were only 3 bits left.
+    Fortunately, there was spare space in the data structure, and so I have
+    moved the internal flags into a new 16-bit field to free up more option
+    bits.
+
+3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
+    but did not set the internal JCHANGED flag - either of these is enough to
+    control the way the "get" function works - but the PCRE_INFO_JCHANGED
+    facility is supposed to tell if (?J) was ever used, so now (?J) at the
+    start sets both bits.
+
+4.  Added options (at build time, compile time, exec time) to change \R from
+    matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
+
+5.  doc/pcresyntax.html was missing from the distribution.
+
+6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
+    compatibility, even though it is no longer used.
+
+7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
+    strtoull to pcrecpp.cc to select the available functions in WIN32 when the
+    windows.h file is present (where different names are used). [This was
+    reversed later after testing - see 16 below.]
+
+8.  Changed all #include <config.h> to #include "config.h". There were also
+    some further <pcre.h> cases that I changed to "pcre.h".
+
+9.  When pcregrep was used with the --colour option, it missed the line ending
+    sequence off the lines that it output.
+
+10. It was pointed out to me that arrays of string pointers cause lots of
+    relocations when a shared library is dynamically loaded. A technique of
+    using a single long string with a table of offsets can drastically reduce
+    these. I have refactored PCRE in four places to do this. The result is
+    dramatic:
+
+      Originally:                          290
+      After changing UCP table:            187
+      After changing error message table:   43
+      After changing table of "verbs"       36
+      After changing table of Posix names   22
+
+    Thanks to the folks working on Gregex for glib for this insight.
+
+11. --disable-stack-for-recursion caused compiling to fail unless -enable-
+    unicode-properties was also set.
+
+12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
+
+13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
+    checked only for CRLF.
+
+14. Added casts to pcretest.c to avoid compiler warnings.
+
+15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
+
+16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
+    and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
+    entirely. This removes changes made in 7 above.
+
+17. The CMake files have been updated, and there is now more information about
+    building with CMake in the NON-UNIX-USE document.
+
+
+Version 7.3 28-Aug-07
+---------------------
+
+ 1. In the rejigging of the build system that eventually resulted in 7.1, the
+    line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
+    brackets there is not right, since it causes compilers to look for an
+    installed pcre.h, not the version that is in the source that is being
+    compiled (which of course may be different). I have changed it back to:
+
+      #include "pcre.h"
+
+    I have a vague recollection that the change was concerned with compiling in
+    different directories, but in the new build system, that is taken care of
+    by the VPATH setting the Makefile.
+
+ 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
+    when the subject happened to end in the byte 0x85 (e.g. if the last
+    character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
+    characters but of course it shouldn't be taken as a newline when it is part
+    of another character. The bug was that, for an unlimited repeat of . in
+    not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
+    characters when looking for a newline.
+
+ 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
+
+ 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
+    in debug output.
+
+ 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
+    long printing in the pcrecpp unittest when running under MinGW.
+
+ 6. ESC_K was left out of the EBCDIC table.
+
+ 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
+    parentheses; I made it 1000, which seemed large enough. Unfortunately, the
+    limit also applies to "virtual nesting" when a pattern is recursive, and in
+    this case 1000 isn't so big. I have been able to remove this limit at the
+    expense of backing off one optimization in certain circumstances. Normally,
+    when pcre_exec() would call its internal match() function recursively and
+    immediately return the result unconditionally, it uses a "tail recursion"
+    feature to save stack. However, when a subpattern that can match an empty
+    string has an unlimited repetition quantifier, it no longer makes this
+    optimization. That gives it a stack frame in which to save the data for
+    checking that an empty string has been matched. Previously this was taken
+    from the 1000-entry workspace that had been reserved. So now there is no
+    explicit limit, but more stack is used.
+
+ 8. Applied Daniel's patches to solve problems with the import/export magic
+    syntax that is required for Windows, and which was going wrong for the
+    pcreposix and pcrecpp parts of the library. These were overlooked when this
+    problem was solved for the main library.
+
+ 9. There were some crude static tests to avoid integer overflow when computing
+    the size of patterns that contain repeated groups with explicit upper
+    limits. As the maximum quantifier is 65535, the maximum group length was
+    set at 30,000 so that the product of these two numbers did not overflow a
+    32-bit integer. However, it turns out that people want to use groups that
+    are longer than 30,000 bytes (though not repeat them that many times).
+    Change 7.0/17 (the refactoring of the way the pattern size is computed) has
+    made it possible to implement the integer overflow checks in a much more
+    dynamic way, which I have now done. The artificial limitation on group
+    length has been removed - we now have only the limit on the total length of
+    the compiled pattern, which depends on the LINK_SIZE setting.
+
+10. Fixed a bug in the documentation for get/copy named substring when
+    duplicate names are permitted. If none of the named substrings are set, the
+    functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
+    empty string.
+
+11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
+    instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
+    because the ] is interpreted as the first data character and the
+    terminating ] is not found. PCRE has been made compatible with Perl in this
+    regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
+    cause memory overwriting.
+
+10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
+    string has been matched (to stop an infinite loop). It was not recognizing
+    a conditional subpattern that could match an empty string if that
+    subpattern was within another subpattern. For example, it looped when
+    trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
+    condition was not nested. This bug has been fixed.
+
+12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
+    past the start of the subject in the presence of bytes with the top bit
+    set, for example "\x8aBCD".
+
+13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
+    (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
+
+14. Optimized (?!) to (*FAIL).
+
+15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
+    This restricts code points to be within the range 0 to 0x10FFFF, excluding
+    the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
+    full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
+    does: it's just the validity check that is more restrictive.
+
+16. Inserted checks for integer overflows during escape sequence (backslash)
+    processing, and also fixed erroneous offset values for syntax errors during
+    backslash processing.
+
+17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
+    for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
+
+18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
+    caused an overrun.
+
+19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
+    something other than just ASCII characters) inside a group that had an
+    unlimited repeat caused a loop at compile time (while checking to see
+    whether the group could match an empty string).
+
+20. Debugging a pattern containing \p or \P could cause a crash. For example,
+    [\P{Any}] did so. (Error in the code for printing property names.)
+
+21. An orphan \E inside a character class could cause a crash.
+
+22. A repeated capturing bracket such as (A)? could cause a wild memory
+    reference during compilation.
+
+23. There are several functions in pcre_compile() that scan along a compiled
+    expression for various reasons (e.g. to see if it's fixed length for look
+    behind). There were bugs in these functions when a repeated \p or \P was
+    present in the pattern. These operators have additional parameters compared
+    with \d, etc, and these were not being taken into account when moving along
+    the compiled data. Specifically:
+
+    (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
+        length.
+
+    (b) An item such as \pL+ within a repeated group could cause crashes or
+        loops.
+
+    (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
+        "reference to non-existent subpattern" error.
+
+    (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
+
+24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
+    characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
+
+25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
+
+26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
+    character were causing crashes (broken optimization).
+
+27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
+    \p or \P) caused a compile-time loop.
+
+28. More problems have arisen in unanchored patterns when CRLF is a valid line
+    break. For example, the unstudied pattern [\r\n]A does not match the string
+    "\r\nA" because change 7.0/46 below moves the current point on by two
+    characters after failing to match at the start. However, the pattern \nA
+    *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
+    the same is true. There doesn't seem any very clean way out of this, but
+    what I have chosen to do makes the common cases work: PCRE now takes note
+    of whether there can be an explicit match for \r or \n anywhere in the
+    pattern, and if so, 7.0/46 no longer applies. As part of this change,
+    there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
+    pattern has explicit CR or LF references.
+
+29. Added (*CR) etc for changing newline setting at start of pattern.
+
+
+Version 7.2 19-Jun-07
+---------------------
+
+ 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
+    which is apparently normally available under Windows.
+
+ 2. Re-jig the pcregrep tests with different newline settings in an attempt
+    to make them independent of the local environment's newline setting.
+
+ 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
+
+ 4. Some of the "internals" tests were previously cut out when the link size
+    was not 2, because the output contained actual offsets. The recent new
+    "Z" feature of pcretest means that these can be cut out, making the tests
+    usable with all link sizes.
+
+ 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
+    stack recursion. This gives a massive performance boost under BSD, but just
+    a small improvement under Linux. However, it saves one field in the frame
+    in all cases.
+
+ 6. Added more features from the forthcoming Perl 5.10:
+
+    (a) (?-n) (where n is a string of digits) is a relative subroutine or
+        recursion call. It refers to the nth most recently opened parentheses.
+
+    (b) (?+n) is also a relative subroutine call; it refers to the nth next
+        to be opened parentheses.
+
+    (c) Conditions that refer to capturing parentheses can be specified
+        relatively, for example, (?(-2)... or (?(+3)...
+
+    (d) \K resets the start of the current match so that everything before
+        is not part of it.
+
+    (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
+
+    (f) \g{name} is another synonym - part of Perl 5.10's unification of
+        reference syntax.
+
+    (g) (?| introduces a group in which the numbering of parentheses in each
+        alternative starts with the same number.
+
+    (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
+
+ 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
+    PCRE_INFO_JCHANGED.
+
+ 8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
+    terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
+    for detecting groups that can match an empty string.
+
+ 9. A pattern with a very large number of alternatives (more than several
+    hundred) was running out of internal workspace during the pre-compile
+    phase, where pcre_compile() figures out how much memory will be needed. A
+    bit of new cunning has reduced the workspace needed for groups with
+    alternatives. The 1000-alternative test pattern now uses 12 bytes of
+    workspace instead of running out of the 4096 that are available.
+
+10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
+
+11. Applied patch from Google to remove an optimization that didn't quite work.
+    The report of the bug said:
+
+      pcrecpp::RE("a*").FullMatch("aaa") matches, while
+      pcrecpp::RE("a*?").FullMatch("aaa") does not, and
+      pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
+
+12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
+    it matched the wrong number of bytes.
+
+
+Version 7.1 24-Apr-07
+---------------------
+
+ 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
+    that is more "standard", making use of automake and other Autotools. There
+    is some re-arrangement of the files and adjustment of comments consequent
+    on this.
+
+ 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
+    for recursive directory scanning broke on some systems because the files
+    are not scanned in any specific order and on different systems the order
+    was different. A call to "sort" has been inserted into RunGrepTest for the
+    approprate test as a short-term fix. In the longer term there may be an
+    alternative.
+
+ 3. I had an email from Eric Raymond about problems translating some of PCRE's
+    man pages to HTML (despite the fact that I distribute HTML pages, some
+    people do their own conversions for various reasons). The problems
+    concerned the use of low-level troff macros .br and .in. I have therefore
+    removed all such uses from the man pages (some were redundant, some could
+    be replaced by .nf/.fi pairs). The 132html script that I use to generate
+    HTML has been updated to handle .nf/.fi and to complain if it encounters
+    .br or .in.
+
+ 4. Updated comments in configure.ac that get placed in config.h.in and also
+    arranged for config.h to be included in the distribution, with the name
+    config.h.generic, for the benefit of those who have to compile without
+    Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
+
+ 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
+    Weber: (1) pcre_internal.h was missing some function renames; (2) updated
+    makevp.bat for the current PCRE, using the additional files
+    makevp_c.txt, makevp_l.txt, and pcregexp.pas.
+
+ 6. A Windows user reported a minor discrepancy with test 2, which turned out
+    to be caused by a trailing space on an input line that had got lost in his
+    copy. The trailing space was an accident, so I've just removed it.
+
+ 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
+    that is needed.
+
+ 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
+    as "const" (a) because they are and (b) because it helps the PHP
+    maintainers who have recently made a script to detect big data structures
+    in the php code that should be moved to the .rodata section. I remembered
+    to update Builducptable as well, so it won't revert if ucptable.h is ever
+    re-created.
+
+ 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
+    pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
+    order to be able to cut out the UTF-8 tables in the latter when UTF-8
+    support is not required. This saves 1.5-2K of code, which is important in
+    some applications.
+
+    Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
+    so as not to refer to the tables, even though these functions will never be
+    called when UTF-8 support is disabled. Otherwise there are problems with a
+    shared library.
+
+10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
+
+    (a) It was defining its arguments as char * instead of void *.
+
+    (b) It was assuming that all moves were upwards in memory; this was true
+        a long time ago when I wrote it, but is no longer the case.
+
+    The emulated memove() is provided for those environments that have neither
+    memmove() nor bcopy(). I didn't think anyone used it these days, but that
+    is clearly not the case, as these two bugs were recently reported.
+
+11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
+    and Detrail to create the HTML documentation, the .txt form of the man
+    pages, and it removes trailing spaces from listed files. It also creates
+    pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
+    case, it wraps all the #defines with #ifndefs. This script should be run
+    before "make dist".
+
+12. Fixed two fairly obscure bugs concerned with quantified caseless matching
+    with Unicode property support.
+
+    (a) For a maximizing quantifier, if the two different cases of the
+        character were of different lengths in their UTF-8 codings (there are
+        some cases like this - I found 11), and the matching function had to
+        back up over a mixture of the two cases, it incorrectly assumed they
+        were both the same length.
+
+    (b) When PCRE was configured to use the heap rather than the stack for
+        recursion during matching, it was not correctly preserving the data for
+        the other case of a UTF-8 character when checking ahead for a match
+        while processing a minimizing repeat. If the check also involved
+        matching a wide character, but failed, corruption could cause an
+        erroneous result when trying to check for a repeat of the original
+        character.
+
+13. Some tidying changes to the testing mechanism:
+
+    (a) The RunTest script now detects the internal link size and whether there
+        is UTF-8 and UCP support by running ./pcretest -C instead of relying on
+        values substituted by "configure". (The RunGrepTest script already did
+        this for UTF-8.) The configure.ac script no longer substitutes the
+        relevant variables.
+
+    (b) The debugging options /B and /D in pcretest show the compiled bytecode
+        with length and offset values. This means that the output is different
+        for different internal link sizes. Test 2 is skipped for link sizes
+        other than 2 because of this, bypassing the problem. Unfortunately,
+        there was also a test in test 3 (the locale tests) that used /B and
+        failed for link sizes other than 2. Rather than cut the whole test out,
+        I have added a new /Z option to pcretest that replaces the length and
+        offset values with spaces. This is now used to make test 3 independent
+        of link size. (Test 2 will be tidied up later.)
+
+14. If erroroffset was passed as NULL to pcre_compile, it provoked a
+    segmentation fault instead of returning the appropriate error message.
+
+15. In multiline mode when the newline sequence was set to "any", the pattern
+    ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
+    This doesn't seem right; it now treats the CRLF combination as the line
+    ending, and so does not match in that case. It's only a pattern such as ^$
+    that would hit this one: something like ^ABC$ would have failed after \r
+    and then tried again after \r\n.
+
+16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
+    in an attempt to make files that differ only in their line terminators
+    compare equal. This works on Linux.
+
+17. Under certain error circumstances pcregrep might try to free random memory
+    as it exited. This is now fixed, thanks to valgrind.
+
+19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
+    "abc\r\n\r\n", it found an unwanted second match after the second \r. This
+    was because its rules for how to advance for /g after matching an empty
+    string at the end of a line did not allow for this case. They now check for
+    it specially.
+
+20. pcretest is supposed to handle patterns and data of any length, by
+    extending its buffers when necessary. It was getting this wrong when the
+    buffer for a data line had to be extended.
+
+21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
+    CRLF as a newline sequence.
+
+22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
+    out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
+    I have nevertheless tidied it up.
+
+23. Added some casts to kill warnings from HP-UX ia64 compiler.
+
+24. Added a man page for pcre-config.
+
+
+Version 7.0 19-Dec-06
+---------------------
+
+ 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
+    moving to gcc 4.1.1.
+
+ 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
+    sys/time.h, which is documented as needed for this function. It doesn't
+    seem to matter on Linux, but it showed up on some releases of OS X.
+
+ 3. It seems that there are systems where bytes whose values are greater than
+    127 match isprint() in the "C" locale. The "C" locale should be the
+    default when a C program starts up. In most systems, only ASCII printing
+    characters match isprint(). This difference caused the output from pcretest
+    to vary, making some of the tests fail. I have changed pcretest so that:
+
+    (a) When it is outputting text in the compiled version of a pattern, bytes
+        other than 32-126 are always shown as hex escapes.
+
+    (b) When it is outputting text that is a matched part of a subject string,
+        it does the same, unless a different locale has been set for the match
+        (using the /L modifier). In this case, it uses isprint() to decide.
+
+ 4. Fixed a major bug that caused incorrect computation of the amount of memory
+    required for a compiled pattern when options that changed within the
+    pattern affected the logic of the preliminary scan that determines the
+    length. The relevant options are -x, and -i in UTF-8 mode. The result was
+    that the computed length was too small. The symptoms of this bug were
+    either the PCRE error "internal error: code overflow" from pcre_compile(),
+    or a glibc crash with a message such as "pcretest: free(): invalid next
+    size (fast)". Examples of patterns that provoked this bug (shown in
+    pcretest format) are:
+
+      /(?-x: )/x
+      /(?x)(?-x: \s*#\s*)/
+      /((?i)[\x{c0}])/8
+      /(?i:[\x{c0}])/8
+
+    HOWEVER: Change 17 below makes this fix obsolete as the memory computation
+    is now done differently.
+
+ 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
+    wrapper classes; (b) implement a new function in the C++ scanner that is
+    more efficient than the old way of doing things because it avoids levels of
+    recursion in the regex matching; (c) add a paragraph to the documentation
+    for the FullMatch() function.
+
+ 6. The escape sequence \n was being treated as whatever was defined as
+    "newline". Not only was this contrary to the documentation, which states
+    that \n is character 10 (hex 0A), but it also went horribly wrong when
+    "newline" was defined as CRLF. This has been fixed.
+
+ 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
+    was being set to -1 for the "end of line" case (supposedly a value that no
+    character can have). Though this value is never used (the check for end of
+    line is "zero bytes in current character"), it caused compiler complaints.
+    I've changed it to 0xffffffff.
+
+ 8. In pcre_version.c, the version string was being built by a sequence of
+    C macros that, in the event of PCRE_PRERELEASE being defined as an empty
+    string (as it is for production releases) called a macro with an empty
+    argument. The C standard says the result of this is undefined. The gcc
+    compiler treats it as an empty string (which was what was wanted) but it is
+    reported that Visual C gives an error. The source has been hacked around to
+    avoid this problem.
+
+ 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
+    builds of pcretest, and changed the call to _setmode() to use _O_BINARY
+    instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
+    of them did).
+
+10. Originally, pcretest opened its input and output without "b"; then I was
+    told that "b" was needed in some environments, so it was added for release
+    5.0 to both the input and output. (It makes no difference on Unix-like
+    systems.) Later I was told that it is wrong for the input on Windows. I've
+    now abstracted the modes into two macros, to make it easier to fiddle with
+    them, and removed "b" from the input mode under Windows.
+
+11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
+
+12. Added -help and --help to pcretest as an official way of being reminded
+    of the options.
+
+13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
+    and pcrecpp.cc because they annoy compilers at high warning levels.
+
+14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
+
+15. Fixed an occurrence of == in configure.ac that should have been = (shell
+    scripts are not C programs :-) and which was not noticed because it works
+    on Linux.
+
+16. pcretest is supposed to handle any length of pattern and data line (as one
+    line or as a continued sequence of lines) by extending its input buffer if
+    necessary. This feature was broken for very long pattern lines, leading to
+    a string of junk being passed to pcre_compile() if the pattern was longer
+    than about 50K.
+
+17. I have done a major re-factoring of the way pcre_compile() computes the
+    amount of memory needed for a compiled pattern. Previously, there was code
+    that made a preliminary scan of the pattern in order to do this. That was
+    OK when PCRE was new, but as the facilities have expanded, it has become
+    harder and harder to keep it in step with the real compile phase, and there
+    have been a number of bugs (see for example, 4 above). I have now found a
+    cunning way of running the real compile function in a "fake" mode that
+    enables it to compute how much memory it would need, while actually only
+    ever using a few hundred bytes of working memory and without too many
+    tests of the mode. This should make future maintenance and development
+    easier. A side effect of this work is that the limit of 200 on the nesting
+    depth of parentheses has been removed (though this was never a serious
+    limitation, I suspect). However, there is a downside: pcre_compile() now
+    runs more slowly than before (30% or more, depending on the pattern). I
+    hope this isn't a big issue. There is no effect on runtime performance.
+
+18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
+    newline (only possible for the last line of a file) and it was a
+    pattern that set a locale (followed by /Lsomething), pcretest crashed.
+
+19. Added additional timing features to pcretest. (1) The -tm option now times
+    matching only, not compiling. (2) Both -t and -tm can be followed, as a
+    separate command line item, by a number that specifies the number of
+    repeats to use when timing. The default is 50000; this gives better
+    precision, but takes uncomfortably long for very large patterns.
+
+20. Extended pcre_study() to be more clever in cases where a branch of a
+    subpattern has no definite first character. For example, (a*|b*)[cd] would
+    previously give no result from pcre_study(). Now it recognizes that the
+    first character must be a, b, c, or d.
+
+21. There was an incorrect error "recursive call could loop indefinitely" if
+    a subpattern (or the entire pattern) that was being tested for matching an
+    empty string contained only one non-empty item after a nested subpattern.
+    For example, the pattern (?>\x{100}*)\d(?R) provoked this error
+    incorrectly, because the \d was being skipped in the check.
+
+22. The pcretest program now has a new pattern option /B and a command line
+    option -b, which is equivalent to adding /B to every pattern. This causes
+    it to show the compiled bytecode, without the additional information that
+    -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
+    is the same as /B/I).
+
+23. A new optimization is now able automatically to treat some sequences such
+    as a*b as a*+b. More specifically, if something simple (such as a character
+    or a simple class like \d) has an unlimited quantifier, and is followed by
+    something that cannot possibly match the quantified thing, the quantifier
+    is automatically "possessified".
+
+24. A recursive reference to a subpattern whose number was greater than 39
+    went wrong under certain circumstances in UTF-8 mode. This bug could also
+    have affected the operation of pcre_study().
+
+25. Realized that a little bit of performance could be had by replacing
+    (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
+
+26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
+
+27. Possessive quantifiers such as a++ were previously implemented by turning
+    them into atomic groups such as ($>a+). Now they have their own opcodes,
+    which improves performance. This includes the automatically created ones
+    from 23 above.
+
+28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
+    lookahead was broken if it was not anchored. PCRE was mistakenly expecting
+    the first matched character to be a colon. This applied both to named and
+    numbered groups.
+
+29. The ucpinternal.h header file was missing its idempotency #ifdef.
+
+30. I was sent a "project" file called libpcre.a.dev which I understand makes
+    building PCRE on Windows easier, so I have included it in the distribution.
+
+31. There is now a check in pcretest against a ridiculously large number being
+    returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
+    loop, the loop is abandoned.
+
+32. Forward references to subpatterns in conditions such as (?(2)...) where
+    subpattern 2 is defined later cause pcre_compile() to search forwards in
+    the pattern for the relevant set of parentheses. This search went wrong
+    when there were unescaped parentheses in a character class, parentheses
+    escaped with \Q...\E, or parentheses in a #-comment in /x mode.
+
+33. "Subroutine" calls and backreferences were previously restricted to
+    referencing subpatterns earlier in the regex. This restriction has now
+    been removed.
+
+34. Added a number of extra features that are going to be in Perl 5.10. On the
+    whole, these are just syntactic alternatives for features that PCRE had
+    previously implemented using the Python syntax or my own invention. The
+    other formats are all retained for compatibility.
+
+    (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
+        as (?P<name>...). The new forms, as well as being in Perl 5.10, are
+        also .NET compatible.
+
+    (b) A recursion or subroutine call to a named group can now be defined as
+        (?&name) as well as (?P>name).
+
+    (c) A backreference to a named group can now be defined as \k<name> or
+        \k'name' as well as (?P=name). The new forms, as well as being in Perl
+        5.10, are also .NET compatible.
+
+    (d) A conditional reference to a named group can now use the syntax
+        (?(<name>) or (?('name') as well as (?(name).
+
+    (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
+        groups (named and numbered) that are never evaluated inline, but can be
+        called as "subroutines" from elsewhere. In effect, the DEFINE condition
+        is always false. There may be only one alternative in such a group.
+
+    (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
+        as the simple (?(R). The condition is true only if the most recent
+        recursion is that of the given number or name. It does not search out
+        through the entire recursion stack.
+
+    (g) The escape \gN or \g{N} has been added, where N is a positive or
+        negative number, specifying an absolute or relative reference.
+
+35. Tidied to get rid of some further signed/unsigned compiler warnings and
+    some "unreachable code" warnings.
+
+36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
+    things, this adds five new scripts.
+
+37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
+    There were also incompatibilities regarding the handling of \Q..\E inside
+    character classes, for example with patterns like [\Qa\E-\Qz\E] where the
+    hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
+
+38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
+    matches an empty string, and forcibly breaks the loop. There were bugs in
+    this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
+    against  aaaa  the result was just "a" rather than "aaaa", for example. Two
+    separate and independent bugs (that affected different cases) have been
+    fixed.
+
+39. Refactored the code to abolish the use of different opcodes for small
+    capturing bracket numbers. This is a tidy that I avoided doing when I
+    removed the limit on the number of capturing brackets for 3.5 back in 2001.
+    The new approach is not only tidier, it makes it possible to reduce the
+    memory needed to fix the previous bug (38).
+
+40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
+    sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
+    processing dot, circumflex, or dollar metacharacters, or #-comments in /x
+    mode.
+
+41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
+    report.
+
+42. Applied patch, originally from Ari Pollak, modified by Google, to allow
+    copy construction and assignment in the C++ wrapper.
+
+43. Updated pcregrep to support "--newline=any". In the process, I fixed a
+    couple of bugs that could have given wrong results in the "--newline=crlf"
+    case.
+
+44. Added a number of casts and did some reorganization of signed/unsigned int
+    variables following suggestions from Dair Grant. Also renamed the variable
+    "this" as "item" because it is a C++ keyword.
+
+45. Arranged for dftables to add
+
+      #include "pcre_internal.h"
+
+    to pcre_chartables.c because without it, gcc 4.x may remove the array
+    definition from the final binary if PCRE is built into a static library and
+    dead code stripping is activated.
+
+46. For an unanchored pattern, if a match attempt fails at the start of a
+    newline sequence, and the newline setting is CRLF or ANY, and the next two
+    characters are CRLF, advance by two characters instead of one.
+
+
+Version 6.7 04-Jul-06
+---------------------
+
+ 1. In order to handle tests when input lines are enormously long, pcretest has
+    been re-factored so that it automatically extends its buffers when
+    necessary. The code is crude, but this _is_ just a test program. The
+    default size has been increased from 32K to 50K.
+
+ 2. The code in pcre_study() was using the value of the re argument before
+    testing it for NULL. (Of course, in any sensible call of the function, it
+    won't be NULL.)
+
+ 3. The memmove() emulation function in pcre_internal.h, which is used on
+    systems that lack both memmove() and bcopy() - that is, hardly ever -
+    was missing a "static" storage class specifier.
+
+ 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
+    containing an extended class (one that cannot be represented by a bitmap
+    because it contains high-valued characters or Unicode property items, e.g.
+    [\pZ]). Almost always one would set UTF-8 mode when processing such a
+    pattern, but PCRE should not loop if you do not (it no longer does).
+    [Detail: two cases were found: (a) a repeated subpattern containing an
+    extended class; (b) a recursive reference to a subpattern that followed a
+    previous extended class. It wasn't skipping over the extended class
+    correctly when UTF-8 mode was not set.]
+
+ 5. A negated single-character class was not being recognized as fixed-length
+    in lookbehind assertions such as (?<=[^f]), leading to an incorrect
+    compile error "lookbehind assertion is not fixed length".
+
+ 6. The RunPerlTest auxiliary script was showing an unexpected difference
+    between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
+    write a Perl script that can interpret lines of an input file either as
+    byte characters or as UTF-8, which is what "perltest" was being required to
+    do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
+    can't do is switch easily at run time between having the "use utf8;" pragma
+    or not. In the end, I fudged it by using the RunPerlTest script to insert
+    "use utf8;" explicitly for the UTF-8 tests.
+
+ 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
+    the end of the subject string, contrary to the documentation and to what
+    Perl does. This was true of both matching functions. Now it matches only at
+    the start of the subject and immediately after *internal* newlines.
+
+ 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
+    a pointer to an int instead of a pointer to an unsigned long int. This
+    caused problems on 64-bit systems.
+
+ 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
+    instance of the 'standard' template library not being so standard".
+
+10. There was no check on the number of named subpatterns nor the maximum
+    length of a subpattern name. The product of these values is used to compute
+    the size of the memory block for a compiled pattern. By supplying a very
+    long subpattern name and a large number of named subpatterns, the size
+    computation could be caused to overflow. This is now prevented by limiting
+    the length of names to 32 characters, and the number of named subpatterns
+    to 10,000.
+
+11. Subpatterns that are repeated with specific counts have to be replicated in
+    the compiled pattern. The size of memory for this was computed from the
+    length of the subpattern and the repeat count. The latter is limited to
+    65535, but there was no limit on the former, meaning that integer overflow
+    could in principle occur. The compiled length of a repeated subpattern is
+    now limited to 30,000 bytes in order to prevent this.
+
+12. Added the optional facility to have named substrings with the same name.
+
+13. Added the ability to use a named substring as a condition, using the
+    Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
+    are numbers (not recommended). Forward references are permitted.
+
+14. Added forward references in named backreferences (if you see what I mean).
+
+15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
+    pattern could run off the end of the subject. For example, the pattern
+    "(?s)(.{1,5})"8 did this with the subject "ab".
+
+16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
+    PCRE_CASELESS was set when matching characters that were quantified with ?
+    or *.
+
+17. A character class other than a single negated character that had a minimum
+    but no maximum quantifier - for example [ab]{6,} - was not handled
+    correctly by pce_dfa_exec(). It would match only one character.
+
+18. A valid (though odd) pattern that looked like a POSIX character
+    class but used an invalid character after [ (for example [[,abc,]]) caused
+    pcre_compile() to give the error "Failed: internal error: code overflow" or
+    in some cases to crash with a glibc free() error. This could even happen if
+    the pattern terminated after [[ but there just happened to be a sequence of
+    letters, a binary zero, and a closing ] in the memory that followed.
+
+19. Perl's treatment of octal escapes in the range \400 to \777 has changed
+    over the years. Originally (before any Unicode support), just the bottom 8
+    bits were taken. Thus, for example, \500 really meant \100. Nowadays the
+    output from "man perlunicode" includes this:
+
+      The regular expression compiler produces polymorphic opcodes.  That
+      is, the pattern adapts to the data and automatically switches to
+      the Unicode character scheme when presented with Unicode data--or
+      instead uses a traditional byte scheme when presented with byte
+      data.
+
+    Sadly, a wide octal escape does not cause a switch, and in a string with
+    no other multibyte characters, these octal escapes are treated as before.
+    Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
+    /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
+    Unicode string.
+
+    I have not perpetrated such confusion in PCRE. Up till now, it took just
+    the bottom 8 bits, as in old Perl. I have now made octal escapes with
+    values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
+    translate to the appropriate multibyte character.
+
+29. Applied some refactoring to reduce the number of warnings from Microsoft
+    and Borland compilers. This has included removing the fudge introduced
+    seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
+    a warning about an unused variable.
+
+21. PCRE has not included VT (character 0x0b) in the set of whitespace
+    characters since release 4.0, because Perl (from release 5.004) does not.
+    [Or at least, is documented not to: some releases seem to be in conflict
+    with the documentation.] However, when a pattern was studied with
+    pcre_study() and all its branches started with \s, PCRE still included VT
+    as a possible starting character. Of course, this did no harm; it just
+    caused an unnecessary match attempt.
+
+22. Removed a now-redundant internal flag bit that recorded the fact that case
+    dependency changed within the pattern. This was once needed for "required
+    byte" processing, but is no longer used. This recovers a now-scarce options
+    bit. Also moved the least significant internal flag bit to the most-
+    significant bit of the word, which was not previously used (hangover from
+    the days when it was an int rather than a uint) to free up another bit for
+    the future.
+
+23. Added support for CRLF line endings as well as CR and LF. As well as the
+    default being selectable at build time, it can now be changed at runtime
+    via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
+    specify that it is scanning data with non-default line endings.
+
+24. Changed the definition of CXXLINK to make it agree with the definition of
+    LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
+
+25. Applied Ian Taylor's patches to avoid using another stack frame for tail
+    recursions. This makes a big different to stack usage for some patterns.
+
+26. If a subpattern containing a named recursion or subroutine reference such
+    as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
+    the space required for the compiled pattern went wrong and gave too small a
+    value. Depending on the environment, this could lead to "Failed: internal
+    error: code overflow at offset 49" or "glibc detected double free or
+    corruption" errors.
+
+27. Applied patches from Google (a) to support the new newline modes and (b) to
+    advance over multibyte UTF-8 characters in GlobalReplace.
+
+28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
+    difference for some implementation of PCRE in some Windows version.
+
+29. Added some extra testing facilities to pcretest:
+
+    \q<number>   in a data line sets the "match limit" value
+    \Q<number>   in a data line sets the "match recursion limt" value
+    -S <number>  sets the stack size, where <number> is in megabytes
+
+    The -S option isn't available for Windows.
+
+
+Version 6.6 06-Feb-06
+---------------------
+
+ 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
+    in pcreposix.h. I have copied the definition from pcre.h.
+
+ 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
+    because pcre.h is no longer a built file.
+
+ 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
+    not normally included in the compiled code.
+
+
+Version 6.5 01-Feb-06
+---------------------
+
+ 1. When using the partial match feature with pcre_dfa_exec(), it was not
+    anchoring the second and subsequent partial matches at the new starting
+    point. This could lead to incorrect results. For example, with the pattern
+    /1234/, partially matching against "123" and then "a4" gave a match.
+
+ 2. Changes to pcregrep:
+
+    (a) All non-match returns from pcre_exec() were being treated as failures
+        to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
+        error message is output. Some extra information is given for the
+        PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
+        probably the only errors that are likely to be caused by users (by
+        specifying a regex that has nested indefinite repeats, for instance).
+        If there are more than 20 of these errors, pcregrep is abandoned.
+
+    (b) A binary zero was treated as data while matching, but terminated the
+        output line if it was written out. This has been fixed: binary zeroes
+        are now no different to any other data bytes.
+
+    (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
+        used to set a locale for matching. The --locale=xxxx long option has
+        been added (no short equivalent) to specify a locale explicitly on the
+        pcregrep command, overriding the environment variables.
+
+    (d) When -B was used with -n, some line numbers in the output were one less
+        than they should have been.
+
+    (e) Added the -o (--only-matching) option.
+
+    (f) If -A or -C was used with -c (count only), some lines of context were
+        accidentally printed for the final match.
+
+    (g) Added the -H (--with-filename) option.
+
+    (h) The combination of options -rh failed to suppress file names for files
+        that were found from directory arguments.
+
+    (i) Added the -D (--devices) and -d (--directories) options.
+
+    (j) Added the -F (--fixed-strings) option.
+
+    (k) Allow "-" to be used as a file name for -f as well as for a data file.
+
+    (l) Added the --colo(u)r option.
+
+    (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
+        is not present by default.
+
+ 3. A nasty bug was discovered in the handling of recursive patterns, that is,
+    items such as (?R) or (?1), when the recursion could match a number of
+    alternatives. If it matched one of the alternatives, but subsequently,
+    outside the recursion, there was a failure, the code tried to back up into
+    the recursion. However, because of the way PCRE is implemented, this is not
+    possible, and the result was an incorrect result from the match.
+
+    In order to prevent this happening, the specification of recursion has
+    been changed so that all such subpatterns are automatically treated as
+    atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
+
+ 4. I had overlooked the fact that, in some locales, there are characters for
+    which isalpha() is true but neither isupper() nor islower() are true. In
+    the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
+    and ordfeminine) are like this. This affected the treatment of \w and \W
+    when they appeared in character classes, but not when they appeared outside
+    a character class. The bit map for "word" characters is now created
+    separately from the results of isalnum() instead of just taking it from the
+    upper, lower, and digit maps. (Plus the underscore character, of course.)
+
+ 5. The above bug also affected the handling of POSIX character classes such as
+    [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
+    permanent tables. Instead, the bit maps for such a class were previously
+    created as the appropriate unions of the upper, lower, and digit bitmaps.
+    Now they are created by subtraction from the [[:word:]] class, which has
+    its own bitmap.
+
+ 6. The [[:blank:]] character class matches horizontal, but not vertical space.
+    It is created by subtracting the vertical space characters (\x09, \x0a,
+    \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
+    subtraction was done in the overall bitmap for a character class, meaning
+    that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
+    be recognized. This bug has been fixed.
+
+ 7. Patches from the folks at Google:
+
+      (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
+      real life, but is still worth protecting against".
+
+      (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
+      regular expressions".
+
+      (c) pcre_scanner.cc: avoid use of std::count() because not all systems
+      have it.
+
+      (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
+      "configure" and the latter not, in order to fix a problem somebody had
+      with compiling the Arg class on HP-UX.
+
+      (e) Improve the error-handling of the C++ wrapper a little bit.
+
+      (f) New tests for checking recursion limiting.
+
+ 8. The pcre_memmove() function, which is used only if the environment does not
+    have a standard memmove() function (and is therefore rarely compiled),
+    contained two bugs: (a) use of int instead of size_t, and (b) it was not
+    returning a result (though PCRE never actually uses the result).
+
+ 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
+    large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
+    returned instead of calling malloc() with an overflowing number that would
+    most likely cause subsequent chaos.
+
+10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
+
+11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
+    with this option is matched, the nmatch and pmatch options of regexec() are
+    ignored.
+
+12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
+    provided in case anyone wants to the the POSIX interface with UTF-8
+    strings.
+
+13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
+    C++ linking (needed for some HP-UX environments).
+
+14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
+    (unused parameter) and in the pcre_printint() function (omitted "default"
+    switch label when the default is to do nothing).
+
+15. Added some code to make it possible, when PCRE is compiled as a C++
+    library, to replace subject pointers for pcre_exec() with a smart pointer
+    class, thus making it possible to process discontinuous strings.
+
+16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
+    much the same function. They were added by different people who were trying
+    to make PCRE easy to compile on non-Unix systems. It has been suggested
+    that PCRE_EXPORT be abolished now that there is more automatic apparatus
+    for compiling on Windows systems. I have therefore replaced it with
+    PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
+    defaults to "extern" for C or "extern C" for C++, which works fine on
+    Unix-like systems. It is now possible to override the value of PCRE_DATA_
+    SCOPE with something explicit in config.h. In addition:
+
+    (a) pcreposix.h still had just "extern" instead of either of these macros;
+        I have replaced it with PCRE_DATA_SCOPE.
+
+    (b) Functions such as _pcre_xclass(), which are internal to the library,
+        but external in the C sense, all had PCRE_EXPORT in their definitions.
+        This is apparently wrong for the Windows case, so I have removed it.
+        (It makes no difference on Unix-like systems.)
+
+17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
+    of recursive calls to match(). This is different to MATCH_LIMIT because
+    that limits the total number of calls to match(), not all of which increase
+    the depth of recursion. Limiting the recursion depth limits the amount of
+    stack (or heap if NO_RECURSE is set) that is used. The default can be set
+    when PCRE is compiled, and changed at run time. A patch from Google adds
+    this functionality to the C++ interface.
+
+18. Changes to the handling of Unicode character properties:
+
+    (a) Updated the table to Unicode 4.1.0.
+
+    (b) Recognize characters that are not in the table as "Cn" (undefined).
+
+    (c) I revised the way the table is implemented to a much improved format
+        which includes recognition of ranges. It now supports the ranges that
+        are defined in UnicodeData.txt, and it also amalgamates other
+        characters into ranges. This has reduced the number of entries in the
+        table from around 16,000 to around 3,000, thus reducing its size
+        considerably. I realized I did not need to use a tree structure after
+        all - a binary chop search is just as efficient. Having reduced the
+        number of entries, I extended their size from 6 bytes to 8 bytes to
+        allow for more data.
+
+    (d) Added support for Unicode script names via properties such as \p{Han}.
+
+19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
+    matching that character.
+
+20. When matching a repeated Unicode property with a minimum greater than zero,
+    (for example \pL{2,}), PCRE could look past the end of the subject if it
+    reached it while seeking the minimum number of characters. This could
+    happen only if some of the characters were more than one byte long, because
+    there is a check for at least the minimum number of bytes.
+
+21. Refactored the implementation of \p and \P so as to be more general, to
+    allow for more different types of property in future. This has changed the
+    compiled form incompatibly. Anybody with saved compiled patterns that use
+    \p or \P will have to recompile them.
+
+22. Added "Any" and "L&" to the supported property types.
+
+23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
+    but give a compile time error if the value is greater than 0xff.
+
+24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
+    accidentally not being installed or uninstalled.
+
+25. The pcre.h file was built from pcre.h.in, but the only changes that were
+    made were to insert the current release number. This seemed silly, because
+    it made things harder for people building PCRE on systems that don't run
+    "configure". I have turned pcre.h into a distributed file, no longer built
+    by "configure", with the version identification directly included. There is
+    no longer a pcre.h.in file.
+
+    However, this change necessitated a change to the pcre-config script as
+    well. It is built from pcre-config.in, and one of the substitutions was the
+    release number. I have updated configure.ac so that ./configure now finds
+    the release number by grepping pcre.h.
+
+26. Added the ability to run the tests under valgrind.
+
+
+Version 6.4 05-Sep-05
+---------------------
+
+ 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
+    "--" to be printed when multiple files were scanned, even when none of the
+    -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
+    consider it to be a bug, and have restored the previous behaviour.
+
+ 2. A couple of code tidies to get rid of compiler warnings.
+
+ 3. The pcretest program used to cheat by referring to symbols in the library
+    whose names begin with _pcre_. These are internal symbols that are not
+    really supposed to be visible externally, and in some environments it is
+    possible to suppress them. The cheating is now confined to including
+    certain files from the library's source, which is a bit cleaner.
+
+ 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
+    file's purpose clearer.
+
+ 5. Reorganized pcre_ucp_findchar().
+
+
+Version 6.3 15-Aug-05
+---------------------
+
+ 1. The file libpcre.pc.in did not have general read permission in the tarball.
+
+ 2. There were some problems when building without C++ support:
+
+    (a) If C++ support was not built, "make install" and "make test" still
+        tried to test it.
+
+    (b) There were problems when the value of CXX was explicitly set. Some
+        changes have been made to try to fix these, and ...
+
+    (c) --disable-cpp can now be used to explicitly disable C++ support.
+
+    (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
+        backslash in a target when C++ was disabled. This confuses some
+        versions of "make", apparently. Using an intermediate variable solves
+        this. (Same for CPP_LOBJ.)
+
+ 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
+    (non-Windows) now includes $(CFLAGS) because these flags are sometimes
+    necessary on certain architectures.
+
+ 4. Added a setting of -export-symbols-regex to the link command to remove
+    those symbols that are exported in the C sense, but actually are local
+    within the library, and not documented. Their names all begin with
+    "_pcre_". This is not a perfect job, because (a) we have to except some
+    symbols that pcretest ("illegally") uses, and (b) the facility isn't always
+    available (and never for static libraries). I have made a note to try to
+    find a way round (a) in the future.
+
+
+Version 6.2 01-Aug-05
+---------------------
+
+ 1. There was no test for integer overflow of quantifier values. A construction
+    such as {1111111111111111} would give undefined results. What is worse, if
+    a minimum quantifier for a parenthesized subpattern overflowed and became
+    negative, the calculation of the memory size went wrong. This could have
+    led to memory overwriting.
+
+ 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
+
+ 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
+    operating environments where this matters.
+
+ 4. Applied Giuseppe Maxia's patch to add additional features for controlling
+    PCRE options from within the C++ wrapper.
+
+ 5. Named capturing subpatterns were not being correctly counted when a pattern
+    was compiled. This caused two problems: (a) If there were more than 100
+    such subpatterns, the calculation of the memory needed for the whole
+    compiled pattern went wrong, leading to an overflow error. (b) Numerical
+    back references of the form \12, where the number was greater than 9, were
+    not recognized as back references, even though there were sufficient
+    previous subpatterns.
+
+ 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
+    versions of gcc, e.g. 2.95.4.
+
+
+Version 6.1 21-Jun-05
+---------------------
+
+ 1. There was one reference to the variable "posix" in pcretest.c that was not
+    surrounded by "#if !defined NOPOSIX".
+
+ 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
+    the cross-check on the old pcre_info() function, for the benefit of the
+    cut-down version of PCRE that is currently imported into Exim.
+
+ 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
+    allocation error. I've done the easy fix, which wastes 2 bytes for sensible
+    patterns that start (?i) but I don't think that matters. The use of (?i) is
+    just an example; this all applies to the other options as well.
+
+ 4. Since libtool seems to echo the compile commands it is issuing, the output
+    from "make" can be reduced a bit by putting "@" in front of each libtool
+    compile command.
+
+ 5. Patch from the folks at Google for configure.in to be a bit more thorough
+    in checking for a suitable C++ installation before trying to compile the
+    C++ stuff. This should fix a reported problem when a compiler was present,
+    but no suitable headers.
+
+ 6. The man pages all had just "PCRE" as their title. I have changed them to
+    be the relevant file name. I have also arranged that these names are
+    retained in the file doc/pcre.txt, which is a concatenation in text format
+    of all the man pages except the little individual ones for each function.
+
+ 7. The NON-UNIX-USE file had not been updated for the different set of source
+    files that come with release 6. I also added a few comments about the C++
+    wrapper.
+
+
+Version 6.0 07-Jun-05
+---------------------
+
+ 1. Some minor internal re-organization to help with my DFA experiments.
+
+ 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
+    didn't matter for the library itself when fully configured, but did matter
+    when compiling without UCP support, or within Exim, where the ucp files are
+    not imported.
+
+ 3. Refactoring of the library code to split up the various functions into
+    different source modules. The addition of the new DFA matching code (see
+    below) to a single monolithic source would have made it really too
+    unwieldy, quite apart from causing all the code to be include in a
+    statically linked application, when only some functions are used. This is
+    relevant even without the DFA addition now that patterns can be compiled in
+    one application and matched in another.
+
+    The downside of splitting up is that there have to be some external
+    functions and data tables that are used internally in different modules of
+    the library but which are not part of the API. These have all had their
+    names changed to start with "_pcre_" so that they are unlikely to clash
+    with other external names.
+
+ 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
+    a different (DFA) algorithm. Although it is slower than the original
+    function, it does have some advantages for certain types of matching
+    problem.
+
+ 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
+    including restarting after a partial match.
+
+ 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
+    defined when compiling for Windows was sent to me. I have put it into the
+    code, though I have no means of testing or verifying it.
+
+ 7. Added the pcre_refcount() auxiliary function.
+
+ 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
+    match before or at the first newline in the subject string. In pcretest,
+    the /f option on a pattern can be used to set this.
+
+ 9. A repeated \w when used in UTF-8 mode with characters greater than 256
+    would behave wrongly. This has been present in PCRE since release 4.0.
+
+10. A number of changes to the pcregrep command:
+
+    (a) Refactored how -x works; insert ^(...)$ instead of setting
+        PCRE_ANCHORED and checking the length, in preparation for adding
+        something similar for -w.
+
+    (b) Added the -w (match as a word) option.
+
+    (c) Refactored the way lines are read and buffered so as to have more
+        than one at a time available.
+
+    (d) Implemented a pcregrep test script.
+
+    (e) Added the -M (multiline match) option. This allows patterns to match
+        over several lines of the subject. The buffering ensures that at least
+        8K, or the rest of the document (whichever is the shorter) is available
+        for matching (and similarly the previous 8K for lookbehind assertions).
+
+    (f) Changed the --help output so that it now says
+
+          -w, --word-regex(p)
+
+        instead of two lines, one with "regex" and the other with "regexp"
+        because that confused at least one person since the short forms are the
+        same. (This required a bit of code, as the output is generated
+        automatically from a table. It wasn't just a text change.)
+
+    (g) -- can be used to terminate pcregrep options if the next thing isn't an
+        option but starts with a hyphen. Could be a pattern or a path name
+        starting with a hyphen, for instance.
+
+    (h) "-" can be given as a file name to represent stdin.
+
+    (i) When file names are being printed, "(standard input)" is used for
+        the standard input, for compatibility with GNU grep. Previously
+        "<stdin>" was used.
+
+    (j) The option --label=xxx can be used to supply a name to be used for
+        stdin when file names are being printed. There is no short form.
+
+    (k) Re-factored the options decoding logic because we are going to add
+        two more options that take data. Such options can now be given in four
+        different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
+
+    (l) Added the -A, -B, and -C options for requesting that lines of context
+        around matches be printed.
+
+    (m) Added the -L option to print the names of files that do not contain
+        any matching lines, that is, the complement of -l.
+
+    (n) The return code is 2 if any file cannot be opened, but pcregrep does
+        continue to scan other files.
+
+    (o) The -s option was incorrectly implemented. For compatibility with other
+        greps, it now suppresses the error message for a non-existent or non-
+        accessible file (but not the return code). There is a new option called
+        -q that suppresses the output of matching lines, which was what -s was
+        previously doing.
+
+    (p) Added --include and --exclude options to specify files for inclusion
+        and exclusion when recursing.
+
+11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
+    Hopefully, it now does.
+
+12. Missing cast in pcre_study().
+
+13. Added an "uninstall" target to the makefile.
+
+14. Replaced "extern" in the function prototypes in Makefile.in with
+    "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
+    world, but is set differently for Windows.
+
+15. Added a second compiling function called pcre_compile2(). The only
+    difference is that it has an extra argument, which is a pointer to an
+    integer error code. When there is a compile-time failure, this is set
+    non-zero, in addition to the error test pointer being set to point to an
+    error message. The new argument may be NULL if no error number is required
+    (but then you may as well call pcre_compile(), which is now just a
+    wrapper). This facility is provided because some applications need a
+    numeric error indication, but it has also enabled me to tidy up the way
+    compile-time errors are handled in the POSIX wrapper.
+
+16. Added VPATH=.libs to the makefile; this should help when building with one
+    prefix path and installing with another. (Or so I'm told by someone who
+    knows more about this stuff than I do.)
+
+17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
+    passes PCRE_DOTALL to the pcre_compile() function, making the "." character
+    match everything, including newlines. This is not POSIX-compatible, but
+    somebody wanted the feature. From pcretest it can be activated by using
+    both the P and the s flags.
+
+18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
+
+19. libpcre.pc was being incorrectly installed as executable.
+
+20. A couple of places in pcretest check for end-of-line by looking for '\n';
+    it now also looks for '\r' so that it will work unmodified on Windows.
+
+21. Added Google's contributed C++ wrapper to the distribution.
+
+22. Added some untidy missing memory free() calls in pcretest, to keep
+    Electric Fence happy when testing.
+
+
+
+Version 5.0 13-Sep-04
+---------------------
+
+ 1. Internal change: literal characters are no longer packed up into items
+    containing multiple characters in a single byte-string. Each character
+    is now matched using a separate opcode. However, there may be more than one
+    byte in the character in UTF-8 mode.
+
+ 2. The pcre_callout_block structure has two new fields: pattern_position and
+    next_item_length. These contain the offset in the pattern to the next match
+    item, and its length, respectively.
+
+ 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
+    insertion of callouts before each pattern item. Added the /C option to
+    pcretest to make use of this.
+
+ 4. On the advice of a Windows user, the lines
+
+      #if defined(_WIN32) || defined(WIN32)
+      _setmode( _fileno( stdout ), 0x8000 );
+      #endif  /* defined(_WIN32) || defined(WIN32) */
+
+    have been added to the source of pcretest. This apparently does useful
+    magic in relation to line terminators.
+
+ 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
+    for the benefit of those environments where the "b" makes a difference.
+
+ 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
+    to know about it. I have put a hack into configure.in that adds in code
+    to set GCC=yes if CC=icc. This seems to end up at a point in the
+    generated configure script that is early enough to affect the setting of
+    compiler options, which is what is needed, but I have no means of testing
+    whether it really works. (The user who reported this had patched the
+    generated configure script, which of course I cannot do.)
+
+    LATER: After change 22 below (new libtool files), the configure script
+    seems to know about icc (and also ecc). Therefore, I have commented out
+    this hack in configure.in.
+
+ 7. Added support for pkg-config (2 patches were sent in).
+
+ 8. Negated POSIX character classes that used a combination of internal tables
+    were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
+    [[:^ascii]]. Typically, they would match almost any characters. The other
+    POSIX classes were not broken in this way.
+
+ 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
+    to find the match, as PCRE was deluded into thinking that the match had to
+    start at the start point or following a newline. The same bug applied to
+    patterns with negative forward assertions or any backward assertions
+    preceding ".*" at the start, unless the pattern required a fixed first
+    character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
+
+10. In UTF-8 mode, when moving forwards in the subject after a failed match
+    starting at the last subject character, bytes beyond the end of the subject
+    string were read.
+
+11. Renamed the variable "class" as "classbits" to make life easier for C++
+    users. (Previously there was a macro definition, but it apparently wasn't
+    enough.)
+
+12. Added the new field "tables" to the extra data so that tables can be passed
+    in at exec time, or the internal tables can be re-selected. This allows
+    a compiled regex to be saved and re-used at a later time by a different
+    program that might have everything at different addresses.
+
+13. Modified the pcre-config script so that, when run on Solaris, it shows a
+    -R library as well as a -L library.
+
+14. The debugging options of pcretest (-d on the command line or D on a
+    pattern) showed incorrect output for anything following an extended class
+    that contained multibyte characters and which was followed by a quantifier.
+
+15. Added optional support for general category Unicode character properties
+    via the \p, \P, and \X escapes. Unicode property support implies UTF-8
+    support. It adds about 90K to the size of the library. The meanings of the
+    inbuilt class escapes such as \d and \s have NOT been changed.
+
+16. Updated pcredemo.c to include calls to free() to release the memory for the
+    compiled pattern.
+
+17. The generated file chartables.c was being created in the source directory
+    instead of in the building directory. This caused the build to fail if the
+    source directory was different from the building directory, and was
+    read-only.
+
+18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
+    file. No doubt somebody will tell me if they don't make sense... Also added
+    Dan Mooney's comments about building on OpenVMS.
+
+19. Added support for partial matching via the PCRE_PARTIAL option for
+    pcre_exec() and the \P data escape in pcretest.
+
+20. Extended pcretest with 3 new pattern features:
+
+    (i)   A pattern option of the form ">rest-of-line" causes pcretest to
+          write the compiled pattern to the file whose name is "rest-of-line".
+          This is a straight binary dump of the data, with the saved pointer to
+          the character tables forced to be NULL. The study data, if any, is
+          written too. After writing, pcretest reads a new pattern.
+
+    (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
+          compiled pattern from the given file. There must not be any
+          occurrences of "<" in the file name (pretty unlikely); if there are,
+          pcretest will instead treat the initial "<" as a pattern delimiter.
+          After reading in the pattern, pcretest goes on to read data lines as
+          usual.
+
+    (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
+          and 16-bit fields in a compiled pattern, to simulate a pattern that
+          was compiled on a host of opposite endianness.
+
+21. The pcre-exec() function can now cope with patterns that were compiled on
+    hosts of opposite endianness, with this restriction:
+
+      As for any compiled expression that is saved and used later, the tables
+      pointer field cannot be preserved; the extra_data field in the arguments
+      to pcre_exec() should be used to pass in a tables address if a value
+      other than the default internal tables were used at compile time.
+
+22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
+    now diagnosed as an error. Previously, most of the time, a negative number
+    would have been treated as zero, but if in addition "ovector" was passed as
+    NULL, a crash could occur.
+
+23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
+    new versions from the libtool 1.5 distribution (the last one is a copy of
+    a file called libtool.m4). This seems to have fixed the need to patch
+    "configure" to support Darwin 1.3 (which I used to do). However, I still
+    had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
+    workstation).
+
+24. Changed the PCRE licence to be the more standard "BSD" licence.
+
+
+Version 4.5 01-Dec-03
+---------------------
+
+ 1. There has been some re-arrangement of the code for the match() function so
+    that it can be compiled in a version that does not call itself recursively.
+    Instead, it keeps those local variables that need separate instances for
+    each "recursion" in a frame on the heap, and gets/frees frames whenever it
+    needs to "recurse". Keeping track of where control must go is done by means
+    of setjmp/longjmp. The whole thing is implemented by a set of macros that
+    hide most of the details from the main code, and operates only if
+    NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
+    "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
+    operating.
+
+    To make it easier for callers to provide specially tailored get/free
+    functions for this usage, two new functions, pcre_stack_malloc, and
+    pcre_stack_free, are used. They are always called in strict stacking order,
+    and the size of block requested is always the same.
+
+    The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
+    PCRE has been compiled to use the stack or the heap for recursion. The
+    -C option of pcretest uses this to show which version is compiled.
+
+    A new data escape \S, is added to pcretest; it causes the amounts of store
+    obtained and freed by both kinds of malloc/free at match time to be added
+    to the output.
+
+ 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
+    what's available on my current Linux desktop machine.
+
+ 3. When matching a UTF-8 string, the test for a valid string at the start has
+    been extended. If start_offset is not zero, PCRE now checks that it points
+    to a byte that is the start of a UTF-8 character. If not, it returns
+    PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
+    this is necessary because there may be backward assertions in the pattern.
+    When matching the same subject several times, it may save resources to use
+    PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
+
+ 4. The code for checking the validity of UTF-8 strings has been tightened so
+    that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
+    containing "overlong sequences".
+
+ 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
+    I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
+    should have been "&", but it just so happened that all the cases this let
+    through by mistake were picked up later in the function.
+
+ 6. I had used a variable called "isblank" - this is a C99 function, causing
+    some compilers to warn. To avoid this, I renamed it (as "blankclass").
+
+ 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
+    prompting; (b) run "./pcretest /dev/null" at the start of the test script
+    so the version is shown; (c) stop "make test" echoing "./RunTest".
+
+ 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
+
+ 9. The prototype for memmove() for systems that don't have it was using
+    size_t, but the inclusion of the header that defines size_t was later. I've
+    moved the #includes for the C headers earlier to avoid this.
+
+10. Added some adjustments to the code to make it easier to compiler on certain
+    special systems:
+
+      (a) Some "const" qualifiers were missing.
+      (b) Added the macro EXPORT before all exported functions; by default this
+          is defined to be empty.
+      (c) Changed the dftables auxiliary program (that builds chartables.c) so
+          that it reads its output file name as an argument instead of writing
+          to the standard output and assuming this can be redirected.
+
+11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
+    class containing characters with values greater than 255, PCRE compilation
+    went into a loop.
+
+12. A recursive reference to a subpattern that was within another subpattern
+    that had a minimum quantifier of zero caused PCRE to crash. For example,
+    (x(y(?2))z)? provoked this bug with a subject that got as far as the
+    recursion. If the recursively-called subpattern itself had a zero repeat,
+    that was OK.
+
+13. In pcretest, the buffer for reading a data line was set at 30K, but the
+    buffer into which it was copied (for escape processing) was still set at
+    1024, so long lines caused crashes.
+
+14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
+    "internal error: code overflow...". This applied to any character class
+    that was followed by a possessive quantifier.
+
+15. Modified the Makefile to add libpcre.la as a prerequisite for
+    libpcreposix.la because I was told this is needed for a parallel build to
+    work.
+
+16. If a pattern that contained .* following optional items at the start was
+    studied, the wrong optimizing data was generated, leading to matching
+    errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
+    matching string must start with a or b or c. The correct conclusion for
+    this pattern is that a match can start with any character.
+
+
+Version 4.4 13-Aug-03
+---------------------
+
+ 1. In UTF-8 mode, a character class containing characters with values between
+    127 and 255 was not handled correctly if the compiled pattern was studied.
+    In fixing this, I have also improved the studying algorithm for such
+    classes (slightly).
+
+ 2. Three internal functions had redundant arguments passed to them. Removal
+    might give a very teeny performance improvement.
+
+ 3. Documentation bug: the value of the capture_top field in a callout is *one
+    more than* the number of the hightest numbered captured substring.
+
+ 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
+    in incorrectly linking with a previously installed version. They now link
+    explicitly with libpcre.la.
+
+ 5. configure.in no longer needs to recognize Cygwin specially.
+
+ 6. A problem in pcre.in for Windows platforms is fixed.
+
+ 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
+    pcretest, it used to include the size of the study block as part of its
+    output. Unfortunately, the structure contains a field that has a different
+    size on different hardware architectures. This meant that the tests that
+    showed this size failed. As the block is currently always of a fixed size,
+    this information isn't actually particularly useful in pcretest output, so
+    I have just removed it.
+
+ 8. Three pre-processor statements accidentally did not start in column 1.
+    Sadly, there are *still* compilers around that complain, even though
+    standard C has not required this for well over a decade. Sigh.
+
+ 9. In pcretest, the code for checking callouts passed small integers in the
+    callout_data field, which is a void * field. However, some picky compilers
+    complained about the casts involved for this on 64-bit systems. Now
+    pcretest passes the address of the small integer instead, which should get
+    rid of the warnings.
+
+10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
+    both compile and run time, and gives an error if an invalid UTF-8 sequence
+    is found. There is a option for disabling this check in cases where the
+    string is known to be correct and/or the maximum performance is wanted.
+
+11. In response to a bug report, I changed one line in Makefile.in from
+
+        -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
+    to
+        -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
+
+    to look similar to other lines, but I have no way of telling whether this
+    is the right thing to do, as I do not use Windows. No doubt I'll get told
+    if it's wrong...
+
+
+Version 4.3 21-May-03
+---------------------
+
+1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
+   Makefile.
+
+2. Some refactoring to improve the quality of the code:
+
+   (i)   The utf8_table... variables are now declared "const".
+
+   (ii)  The code for \cx, which used the "case flipping" table to upper case
+         lower case letters, now just substracts 32. This is ASCII-specific,
+         but the whole concept of \cx is ASCII-specific, so it seems
+         reasonable.
+
+   (iii) PCRE was using its character types table to recognize decimal and
+         hexadecimal digits in the pattern. This is silly, because it handles
+         only 0-9, a-f, and A-F, but the character types table is locale-
+         specific, which means strange things might happen. A private
+         table is now used for this - though it costs 256 bytes, a table is
+         much faster than multiple explicit tests. Of course, the standard
+         character types table is still used for matching digits in subject
+         strings against \d.
+
+   (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
+         ending in _t are). So I've renamed it as ESC_tee.
+
+3. The first argument for regexec() in the POSIX wrapper should have been
+   defined as "const".
+
+4. Changed pcretest to use malloc() for its buffers so that they can be
+   Electric Fenced for debugging.
+
+5. There were several places in the code where, in UTF-8 mode, PCRE would try
+   to read one or more bytes before the start of the subject string. Often this
+   had no effect on PCRE's behaviour, but in some circumstances it could
+   provoke a segmentation fault.
+
+6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
+   to try to read one or more bytes before the start of the subject string.
+
+7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
+   UTF-8 support could misbehave in various ways if the subject string
+   contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
+   area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
+   back over UTF-8 characters.)
+
+
+Version 4.2 14-Apr-03
+---------------------
+
+1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
+
+2. Changes to the building process, supplied by Ronald Landheer-Cieslak
+     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
+     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
+     [WIN_PREFIX]: new variable, "cyg" for Cygwin
+     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
+       and BUILD_EXEEXT
+     Note: automatic setting of the BUILD variables is not yet working
+     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
+       compile-time but not at link-time
+     [LINK]: use for linking executables only
+     make different versions for Windows and non-Windows
+     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
+       libraries
+     [LINK_FOR_BUILD]: new variable
+     [OBJEXT]: use throughout
+     [EXEEXT]: use throughout
+     <winshared>: new target
+     <wininstall>: new target
+     <dftables.o>: use native compiler
+     <dftables>: use native linker
+     <install>: handle Windows platform correctly
+     <clean>: ditto
+     <check>: ditto
+     copy DLL to top builddir before testing
+
+   As part of these changes, -no-undefined was removed again. This was reported
+   to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
+   in any case.
+
+3. Some tidies to get rid of compiler warnings:
+
+   . In the match_data structure, match_limit was an unsigned long int, whereas
+     match_call_count was an int. I've made them both unsigned long ints.
+
+   . In pcretest the fact that a const uschar * doesn't automatically cast to
+     a void * provoked a warning.
+
+   . Turning on some more compiler warnings threw up some "shadow" variables
+     and a few more missing casts.
+
+4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
+   option, a class that contained a single character with a value between 128
+   and 255 (e.g. /[\xFF]/) caused PCRE to crash.
+
+5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
+   option, a class that contained several characters, but with at least one
+   whose value was between 128 and 255 caused PCRE to crash.
+
+
+Version 4.1 12-Mar-03
+---------------------
+
+1. Compiling with gcc -pedantic found a couple of places where casts were
+needed, and a string in dftables.c that was longer than standard compilers are
+required to support.
+
+2. Compiling with Sun's compiler found a few more places where the code could
+be tidied up in order to avoid warnings.
+
+3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
+first of these names is deprecated in the latest Autoconf in favour of the name
+CC_FOR_BUILD, because "host" is typically used to mean the system on which the
+compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
+analogy I have changed it to CFLAGS_FOR_BUILD.
+
+4. Added -no-undefined to the linking command in the Makefile, because this is
+apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
+linking step for the pcreposix library.
+
+5. PCRE was failing to diagnose the case of two named groups with the same
+name.
+
+6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
+literal character that is needed in the subject for a match, and scans along to
+ensure that it is present before embarking on the full matching process. This
+saves time in cases of nested unlimited repeats that are never going to match.
+Problem: the scan can take a lot of time if the subject is very long (e.g.
+megabytes), thus penalizing straightforward matches. It is now done only if the
+amount of subject to be scanned is less than 1000 bytes.
+
+7. A lesser problem with the same optimization is that it was recording the
+first character of an anchored pattern as "needed", thus provoking a search
+right along the subject, even when the first match of the pattern was going to
+fail. The "needed" character is now not set for anchored patterns, unless it
+follows something in the pattern that is of non-fixed length. Thus, it still
+fulfils its original purpose of finding quick non-matches in cases of nested
+unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
+
+
+Version 4.0 17-Feb-03
+---------------------
+
+1. If a comment in an extended regex that started immediately after a meta-item
+extended to the end of string, PCRE compiled incorrect data. This could lead to
+all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
+
+2. Moved to autoconf 2.53 and libtool 1.4.2.
+
+3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
+the special perltest8 script is no longer needed - all the tests can be run
+from a single perltest script.
+
+4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
+by \s. It has now been removed in PCRE. This means it isn't recognized as
+whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
+class [:space:] *does* include VT, thereby creating a mess.
+
+5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
+space and tab.
+
+6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
+its new features into the main test script, reducing the number of scripts.
+
+7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
+were backward compatible, and made the (?i) apply to the whole pattern, as if
+/i were given. Now it behaves more logically, and applies the option setting
+only to what follows. PCRE has been changed to follow suit. However, if it
+finds options settings right at the start of the pattern, it extracts them into
+the global options, as before. Thus, they show up in the info data.
+
+8. Added support for the \Q...\E escape sequence. Characters in between are
+treated as literals. This is slightly different from Perl in that $ and @ are
+also handled as literals inside the quotes. In Perl, they will cause variable
+interpolation. Note the following examples:
+
+    Pattern            PCRE matches      Perl matches
+
+    \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
+    \Qabc\$xyz\E       abc\$xyz          abc\$xyz
+    \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
+
+For compatibility with Perl, \Q...\E sequences are recognized inside character
+classes as well as outside them.
+
+9. Re-organized 3 code statements in pcretest to avoid "overflow in
+floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
+(size_t) cast to one statement in pcretest and one in pcreposix to avoid
+signed/unsigned warnings.
+
+10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
+option for pcretest, so I've replaced it by a simple function that does just
+that job.
+
+11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
+"pcregrep -".
+
+12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
+Java package. This provides some syntactic sugar for simple cases of what my
+documentation calls "once-only subpatterns". A pattern such as x*+ is the same
+as (?>x*). In other words, if what is inside (?>...) is just a single repeated
+item, you can use this simplified notation. Note that only makes sense with
+greedy quantifiers. Consequently, the use of the possessive quantifier forces
+greediness, whatever the setting of the PCRE_UNGREEDY option.
+
+13. A change of greediness default within a pattern was not taking effect at
+the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
+subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
+was abstracted outside.
+
+14. PCRE now supports the \G assertion. It is true when the current matching
+position is at the start point of the match. This differs from \A when the
+starting offset is non-zero. Used with the /g option of pcretest (or similar
+code), it works in the same way as it does for Perl's /g option. If all
+alternatives of a regex begin with \G, the expression is anchored to the start
+match position, and the "anchored" flag is set in the compiled expression.
+
+15. Some bugs concerning the handling of certain option changes within patterns
+have been fixed. These applied to options other than (?ims). For example,
+"a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
+been the other way round. Some of this was related to change 7 above.
+
+16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
+features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
+and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
+POSIX classes only within a class (e.g. /[[:alpha:]]/).
+
+17. Added support for Perl's \C escape. This matches one byte, even in UTF8
+mode. Unlike ".", it always matches newline, whatever the setting of
+PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
+assertions. Perl allows it, but it doesn't (in general) work because it can't
+calculate the length of the lookbehind. At least, that's the case for Perl
+5.8.0 - I've been told they are going to document that it doesn't work in
+future.
+
+18. Added an error diagnosis for escapes that PCRE does not support: these are
+\L, \l, \N, \P, \p, \U, \u, and \X.
+
+19. Although correctly diagnosing a missing ']' in a character class, PCRE was
+reading past the end of the pattern in cases such as /[abcd/.
+
+20. PCRE was getting more memory than necessary for patterns with classes that
+contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
+
+21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
+compiling PCRE for use with Virtual Pascal.
+
+22. Small fix to the Makefile to make it work properly if the build is done
+outside the source tree.
+
+23. Added a new extension: a condition to go with recursion. If a conditional
+subpattern starts with (?(R) the "true" branch is used if recursion has
+happened, whereas the "false" branch is used only at the top level.
+
+24. When there was a very long string of literal characters (over 255 bytes
+without UTF support, over 250 bytes with UTF support), the computation of how
+much memory was required could be incorrect, leading to segfaults or other
+strange effects.
+
+25. PCRE was incorrectly assuming anchoring (either to start of subject or to
+start of line for a non-DOTALL pattern) when a pattern started with (.*) and
+there was a subsequent back reference to those brackets. This meant that, for
+example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
+possible to check for precisely this case. All we can do is abandon the
+optimization if .* occurs inside capturing brackets when there are any back
+references whatsoever. (See below for a better fix that came later.)
+
+26. The handling of the optimization for finding the first character of a
+non-anchored pattern, and for finding a character that is required later in the
+match were failing in some cases. This didn't break the matching; it just
+failed to optimize when it could. The way this is done has been re-implemented.
+
+27. Fixed typo in error message for invalid (?R item (it said "(?p").
+
+28. Added a new feature that provides some of the functionality that Perl
+provides with (?{...}). The facility is termed a "callout". The way it is done
+in PCRE is for the caller to provide an optional function, by setting
+pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
+global variable. By default it is unset, which disables all calling out. To get
+the function called, the regex must include (?C) at appropriate points. This
+is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
+This provides a means of identifying different callout points. When PCRE
+reaches such a point in the regex, if pcre_callout has been set, the external
+function is called. It is provided with data in a structure called
+pcre_callout_block, which is defined in pcre.h. If the function returns 0,
+matching continues; if it returns a non-zero value, the match at the current
+point fails. However, backtracking will occur if possible. [This was changed
+later and other features added - see item 49 below.]
+
+29. pcretest is upgraded to test the callout functionality. It provides a
+callout function that displays information. By default, it shows the start of
+the match and the current position in the text. There are some new data escapes
+to vary what happens:
+
+    \C+         in addition, show current contents of captured substrings
+    \C-         do not supply a callout function
+    \C!n        return 1 when callout number n is reached
+    \C!n!m      return 1 when callout number n is reached for the mth time
+
+30. If pcregrep was called with the -l option and just a single file name, it
+output "<stdin>" if a match was found, instead of the file name.
+
+31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
+slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
+pcre_exec(). This saves a malloc/free per call. The default value of
+POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
+when configuring.
+
+32. The default maximum size of a compiled pattern is 64K. There have been a
+few cases of people hitting this limit. The code now uses macros to handle the
+storing of links as offsets within the compiled pattern. It defaults to 2-byte
+links, but this can be changed to 3 or 4 bytes by --with-link-size when
+configuring. Tests 2 and 5 work only with 2-byte links because they output
+debugging information about compiled patterns.
+
+33. Internal code re-arrangements:
+
+(a) Moved the debugging function for printing out a compiled regex into
+    its own source file (printint.c) and used #include to pull it into
+    pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
+    separate copies.
+
+(b) Defined the list of op-code names for debugging as a macro in
+    internal.h so that it is next to the definition of the opcodes.
+
+(c) Defined a table of op-code lengths for simpler skipping along compiled
+    code. This is again a macro in internal.h so that it is next to the
+    definition of the opcodes.
+
+34. Added support for recursive calls to individual subpatterns, along the
+lines of Robin Houston's patch (but implemented somewhat differently).
+
+35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
+allow it to read and process whole directories in Win32. This code was
+contributed by Lionel Fourquaux; it has not been tested by me.
+
+36. Added support for named subpatterns. The Python syntax (?P<name>...) is
+used to name a group. Names consist of alphanumerics and underscores, and must
+be unique. Back references use the syntax (?P=name) and recursive calls use
+(?P>name) which is a PCRE extension to the Python extension. Groups still have
+numbers. The function pcre_fullinfo() can be used after compilation to extract
+a name/number map. There are three relevant calls:
+
+  PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
+  PCRE_INFO_NAMECOUNT            yields the number of entries
+  PCRE_INFO_NAMETABLE            yields a pointer to the map.
+
+The map is a vector of fixed-size entries. The size of each entry depends on
+the length of the longest name used. The first two bytes of each entry are the
+group number, most significant byte first. There follows the corresponding
+name, zero terminated. The names are in alphabetical order.
+
+37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
+case instead of 255. Making it the same both with and without UTF-8 support
+means that the same test output works with both.
+
+38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
+calling malloc() with a zero argument.
+
+39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
+optimization. I've improved things by keeping a bitmap of backreferences with
+numbers 1-31 so that if .* occurs inside capturing brackets that are not in
+fact referenced, the optimization can be applied. It is unlikely that a
+relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
+the match to follow \n) will appear inside brackets with a number greater than
+31, but if it does, any back reference > 31 suppresses the optimization.
+
+40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
+of disabling numbered capturing parentheses. Any opening parenthesis that is
+not followed by ? behaves as if it were followed by ?: but named parentheses
+can still be used for capturing (and they will acquire numbers in the usual
+way).
+
+41. Redesigned the return codes from the match() function into yes/no/error so
+that errors can be passed back from deep inside the nested calls. A malloc
+failure while inside a recursive subpattern call now causes the
+PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
+
+42. It is now possible to set a limit on the number of times the match()
+function is called in a call to pcre_exec(). This facility makes it possible to
+limit the amount of recursion and backtracking, though not in a directly
+obvious way, because the match() function is used in a number of different
+circumstances. The count starts from zero for each position in the subject
+string (for non-anchored patterns). The default limit is, for compatibility, a
+large number, namely 10 000 000. You can change this in two ways:
+
+(a) When configuring PCRE before making, you can use --with-match-limit=n
+    to set a default value for the compiled library.
+
+(b) For each call to pcre_exec(), you can pass a pcre_extra block in which
+    a different value is set. See 45 below.
+
+If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
+
+43. Added a new function pcre_config(int, void *) to enable run-time extraction
+of things that can be changed at compile time. The first argument specifies
+what is wanted and the second points to where the information is to be placed.
+The current list of available information is:
+
+  PCRE_CONFIG_UTF8
+
+The output is an integer that is set to one if UTF-8 support is available;
+otherwise it is set to zero.
+
+  PCRE_CONFIG_NEWLINE
+
+The output is an integer that it set to the value of the code that is used for
+newline. It is either LF (10) or CR (13).
+
+  PCRE_CONFIG_LINK_SIZE
+
+The output is an integer that contains the number of bytes used for internal
+linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
+
+  PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
+
+The output is an integer that contains the threshold above which the POSIX
+interface uses malloc() for output vectors. See item 31 above.
+
+  PCRE_CONFIG_MATCH_LIMIT
+
+The output is an unsigned integer that contains the default limit of the number
+of match() calls in a pcre_exec() execution. See 42 above.
+
+44. pcretest has been upgraded by the addition of the -C option. This causes it
+to extract all the available output from the new pcre_config() function, and to
+output it. The program then exits immediately.
+
+45. A need has arisen to pass over additional data with calls to pcre_exec() in
+order to support additional features. One way would have been to define
+pcre_exec2() (for example) with extra arguments, but this would not have been
+extensible, and would also have required all calls to the original function to
+be mapped to the new one. Instead, I have chosen to extend the mechanism that
+is used for passing in "extra" data from pcre_study().
+
+The pcre_extra structure is now exposed and defined in pcre.h. It currently
+contains the following fields:
+
+  flags         a bitmap indicating which of the following fields are set
+  study_data    opaque data from pcre_study()
+  match_limit   a way of specifying a limit on match() calls for a specific
+                  call to pcre_exec()
+  callout_data  data for callouts (see 49 below)
+
+The flag bits are also defined in pcre.h, and are
+
+  PCRE_EXTRA_STUDY_DATA
+  PCRE_EXTRA_MATCH_LIMIT
+  PCRE_EXTRA_CALLOUT_DATA
+
+The pcre_study() function now returns one of these new pcre_extra blocks, with
+the actual study data pointed to by the study_data field, and the
+PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
+before. That is, this change is entirely upwards-compatible and requires no
+change to existing code.
+
+If you want to pass in additional data to pcre_exec(), you can either place it
+in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
+block.
+
+46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
+data string contains the escape sequence \M, pcretest calls pcre_exec() several
+times with different match limits, until it finds the minimum value needed for
+pcre_exec() to complete. The value is then output. This can be instructive; for
+most simple matches the number is quite small, but for pathological cases it
+gets very large very quickly.
+
+47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
+returns the size of the data block pointed to by the study_data field in a
+pcre_extra block, that is, the value that was passed as the argument to
+pcre_malloc() when PCRE was getting memory in which to place the information
+created by pcre_study(). The fourth argument should point to a size_t variable.
+pcretest has been extended so that this information is shown after a successful
+pcre_study() call when information about the compiled regex is being displayed.
+
+48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
+because what follows is always an absolute path. (Later: it turns out that this
+is more than cosmetic for MinGW, because it doesn't like empty path
+components.)
+
+49. Some changes have been made to the callout feature (see 28 above):
+
+(i)  A callout function now has three choices for what it returns:
+
+       0  =>  success, carry on matching
+     > 0  =>  failure at this point, but backtrack if possible
+     < 0  =>  serious error, return this value from pcre_exec()
+
+     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
+     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
+     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
+     use by callout functions. It will never be used by PCRE itself.
+
+(ii) The pcre_extra structure (see 45 above) has a void * field called
+     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
+     pcre_callout_block structure has a field of the same name. The contents of
+     the field passed in the pcre_extra structure are passed to the callout
+     function in the corresponding field in the callout block. This makes it
+     easier to use the same callout-containing regex from multiple threads. For
+     testing, the pcretest program has a new data escape
+
+       \C*n        pass the number n (may be negative) as callout_data
+
+     If the callout function in pcretest receives a non-zero value as
+     callout_data, it returns that value.
+
+50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
+there were some redundant $(CFLAGS) in commands that are now specified as
+$(LINK), which already includes $(CFLAGS).
+
+51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
+has been compiled with UTF-8 support *and* pcre_compile() has been compiled
+with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
+one-byte characters throughout. Note that case-insensitive matching applies
+only to characters whose values are less than 256. PCRE doesn't support the
+notion of cases for higher-valued characters.
+
+(i)   A character class whose characters are all within 0-255 is handled as
+      a bit map, and the map is inverted for negative classes. Previously, a
+      character > 255 always failed to match such a class; however it should
+      match if the class was a negative one (e.g. [^ab]). This has been fixed.
+
+(ii)  A negated character class with a single character < 255 is coded as
+      "not this character" (OP_NOT). This wasn't working properly when the test
+      character was multibyte, either singly or repeated.
+
+(iii) Repeats of multibyte characters are now handled correctly in UTF-8
+      mode, for example: \x{100}{2,3}.
+
+(iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
+      singly or repeated) now correctly test multibyte characters. However,
+      PCRE doesn't recognize any characters with values greater than 255 as
+      digits, spaces, or word characters. Such characters always match \D, \S,
+      and \W, and never match \d, \s, or \w.
+
+(v)   Classes may now contain characters and character ranges with values
+      greater than 255. For example: [ab\x{100}-\x{400}].
+
+(vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
+      PCRE in UTF-8 mode.
+
+52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
+PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
+retained for backwards compatibility. (Note that LASTLITERAL is also a byte
+value.)
+
+53. The single man page has become too large. I have therefore split it up into
+a number of separate man pages. These also give rise to individual HTML pages;
+these are now put in a separate directory, and there is an index.html page that
+lists them all. Some hyperlinking between the pages has been installed.
+
+54. Added convenience functions for handling named capturing parentheses.
+
+55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
+aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
+true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
+are faulted.
+
+56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
+calling configure. These values are used when compiling the dftables.c program
+which is run to generate the source of the default character tables. They
+default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
+you will need to set these values.
+
+57. Updated the building process for Windows DLL, as provided by Fred Cox.
+
+
+Version 3.9 02-Jan-02
+---------------------
+
+1. A bit of extraneous text had somehow crept into the pcregrep documentation.
+
+2. If --disable-static was given, the building process failed when trying to
+build pcretest and pcregrep. (For some reason it was using libtool to compile
+them, which is not right, as they aren't part of the library.)
+
+
+Version 3.8 18-Dec-01
+---------------------
+
+1. The experimental UTF-8 code was completely screwed up. It was packing the
+bytes in the wrong order. How dumb can you get?
+
+
+Version 3.7 29-Oct-01
+---------------------
+
+1. In updating pcretest to check change 1 of version 3.6, I screwed up.
+This caused pcretest, when used on the test data, to segfault. Unfortunately,
+this didn't happen under Solaris 8, where I normally test things.
+
+2. The Makefile had to be changed to make it work on BSD systems, where 'make'
+doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
+isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
+this fix an hour or so after the initial 3.7 release.)
+
+
+Version 3.6 23-Oct-01
+---------------------
+
+1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
+offsets passed as NULL with zero offset count.
+
+2. The config.guess and config.sub files had not been updated when I moved to
+the latest autoconf.
+
+
+Version 3.5 15-Aug-01
+---------------------
+
+1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
+had been forgotten.
+
+2. By using declared but undefined structures, we can avoid using "void"
+definitions in pcre.h while keeping the internal definitions of the structures
+private.
+
+3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
+user point of view, this means that both static and shared libraries are built
+by default, but this can be individually controlled. More of the work of
+handling this static/shared cases is now inside libtool instead of PCRE's make
+file.
+
+4. The pcretest utility is now installed along with pcregrep because it is
+useful for users (to test regexs) and by doing this, it automatically gets
+relinked by libtool. The documentation has been turned into a man page, so
+there are now .1, .txt, and .html versions in /doc.
+
+5. Upgrades to pcregrep:
+   (i)   Added long-form option names like gnu grep.
+   (ii)  Added --help to list all options with an explanatory phrase.
+   (iii) Added -r, --recursive to recurse into sub-directories.
+   (iv)  Added -f, --file to read patterns from a file.
+
+6. pcre_exec() was referring to its "code" argument before testing that
+argument for NULL (and giving an error if it was NULL).
+
+7. Upgraded Makefile.in to allow for compiling in a different directory from
+the source directory.
+
+8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
+options bits, the pointer it was passed was to an int instead of to an unsigned
+long int. This mattered only on 64-bit systems.
+
+9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
+generated) instead of pcre.in, which it its source. Also made the same change
+in several of the .c files.
+
+10. A new release of gcc defines printf() as a macro, which broke pcretest
+because it had an ifdef in the middle of a string argument for printf(). Fixed
+by using separate calls to printf().
+
+11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
+script, to force use of CR or LF instead of \n in the source. On non-Unix
+systems, the value can be set in config.h.
+
+12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
+absolute limit. Changed the text of the error message to make this clear, and
+likewise updated the man page.
+
+13. The limit of 99 on the number of capturing subpatterns has been removed.
+The new limit is 65535, which I hope will not be a "real" limit.
+
+
+Version 3.4 22-Aug-00
+---------------------
+
+1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
+
+2. Diagnose condition (?(0) as an error instead of crashing on matching.
+
+
+Version 3.3 01-Aug-00
+---------------------
+
+1. If an octal character was given, but the value was greater than \377, it
+was not getting masked to the least significant bits, as documented. This could
+lead to crashes in some systems.
+
+2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
+the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
+
+3. Added the functions pcre_free_substring() and pcre_free_substring_list().
+These just pass their arguments on to (pcre_free)(), but they are provided
+because some uses of PCRE bind it to non-C systems that can call its functions,
+but cannot call free() or pcre_free() directly.
+
+4. Add "make test" as a synonym for "make check". Corrected some comments in
+the Makefile.
+
+5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
+Makefile.
+
+6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
+command called pgrep for grepping around the active processes.
+
+7. Added the beginnings of support for UTF-8 character strings.
+
+8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
+RANLIB to ./ltconfig so that they are used by libtool. I think these are all
+the relevant ones. (AR is not passed because ./ltconfig does its own figuring
+out for the ar command.)
+
+
+Version 3.2 12-May-00
+---------------------
+
+This is purely a bug fixing release.
+
+1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
+of ZA. This was just one example of several cases that could provoke this bug,
+which was introduced by change 9 of version 2.00. The code for breaking
+infinite loops after an iteration that matches an empty string was't working
+correctly.
+
+2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
+when matched against abbab (for example). After matching an empty string, it
+wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
+caused it to match further down the string than it should.
+
+3. The code contained an inclusion of sys/types.h. It isn't clear why this
+was there because it doesn't seem to be needed, and it causes trouble on some
+systems, as it is not a Standard C header. It has been removed.
+
+4. Made 4 silly changes to the source to avoid stupid compiler warnings that
+were reported on the Macintosh. The changes were from
+
+  while ((c = *(++ptr)) != 0 && c != '\n');
+to
+  while ((c = *(++ptr)) != 0 && c != '\n') ;
+
+Totally extraordinary, but if that's what it takes...
+
+5. PCRE is being used in one environment where neither memmove() nor bcopy() is
+available. Added HAVE_BCOPY and an autoconf test for it; if neither
+HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
+assumes the way PCRE uses memmove() (always moving upwards).
+
+6. PCRE is being used in one environment where strchr() is not available. There
+was only one use in pcre.c, and writing it out to avoid strchr() probably gives
+faster code anyway.
+
+
+Version 3.1 09-Feb-00
+---------------------
+
+The only change in this release is the fixing of some bugs in Makefile.in for
+the "install" target:
+
+(1) It was failing to install pcreposix.h.
+
+(2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
+
+
+Version 3.0 01-Feb-00
+---------------------
+
+1. Add support for the /+ modifier to perltest (to output $` like it does in
+pcretest).
+
+2. Add support for the /g modifier to perltest.
+
+3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
+matches null strings.
+
+4. Fix perltest so that it doesn't do unwanted things when fed an empty
+pattern. Perl treats empty patterns specially - it reuses the most recent
+pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
+effect.
+
+5. The POSIX interface was broken in that it was just handing over the POSIX
+captured string vector to pcre_exec(), but (since release 2.00) PCRE has
+required a bigger vector, with some working space on the end. This means that
+the POSIX wrapper now has to get and free some memory, and copy the results.
+
+6. Added some simple autoconf support, placing the test data and the
+documentation in separate directories, re-organizing some of the
+information files, and making it build pcre-config (a GNU standard). Also added
+libtool support for building PCRE as a shared library, which is now the
+default.
+
+7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
+09 are not valid octal constants. Single digits will be used for minor values
+less than 10.
+
+8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
+existing programs that set these in the POSIX interface can use PCRE without
+modification.
+
+9. Added a new function, pcre_fullinfo() with an extensible interface. It can
+return all that pcre_info() returns, plus additional data. The pcre_info()
+function is retained for compatibility, but is considered to be obsolete.
+
+10. Added experimental recursion feature (?R) to handle one common case that
+Perl 5.6 will be able to do with (?p{...}).
+
+11. Added support for POSIX character classes like [:alpha:], which Perl is
+adopting.
+
+
+Version 2.08 31-Aug-99
+----------------------
+
+1. When startoffset was not zero and the pattern began with ".*", PCRE was not
+trying to match at the startoffset position, but instead was moving forward to
+the next newline as if a previous match had failed.
+
+2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
+and could get into a loop if a null string was matched other than at the start
+of the subject.
+
+3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
+be distinguished at compile time, and for completeness also added PCRE_DATE.
+
+5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
+in GnuWin32 environments.
+
+
+Version 2.07 29-Jul-99
+----------------------
+
+1. The documentation is now supplied in plain text form and HTML as well as in
+the form of man page sources.
+
+2. C++ compilers don't like assigning (void *) values to other pointer types.
+In particular this affects malloc(). Although there is no problem in Standard
+C, I've put in casts to keep C++ compilers happy.
+
+3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
+should be (const char *).
+
+4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
+be useful for non-Unix systems who don't want to bother with the POSIX stuff.
+However, I haven't made this a standard facility. The documentation doesn't
+mention it, and the Makefile doesn't support it.
+
+5. The Makefile now contains an "install" target, with editable destinations at
+the top of the file. The pcretest program is not installed.
+
+6. pgrep -V now gives the PCRE version number and date.
+
+7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
+causing the entire string to be ignored, instead of just the last character.
+
+8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
+non-matching string, it can take a very, very long time, even for strings of
+quite modest length, because of the nested recursion. PCRE now does better in
+some of these cases. It does this by remembering the last required literal
+character in the pattern, and pre-searching the subject to ensure it is present
+before running the real match. In other words, it applies a heuristic to detect
+some types of certain failure quickly, and in the above example, if presented
+with a string that has no trailing " it gives "no match" very quickly.
+
+9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
+other alternatives are tried instead.
+
+
+Version 2.06 09-Jun-99
+----------------------
+
+1. Change pcretest's output for amount of store used to show just the code
+space, because the remainder (the data block) varies in size between 32-bit and
+64-bit systems.
+
+2. Added an extra argument to pcre_exec() to supply an offset in the subject to
+start matching at. This allows lookbehinds to work when searching for multiple
+occurrences in a string.
+
+3. Added additional options to pcretest for testing multiple occurrences:
+
+   /+   outputs the rest of the string that follows a match
+   /g   loops for multiple occurrences, using the new startoffset argument
+   /G   loops for multiple occurrences by passing an incremented pointer
+
+4. PCRE wasn't doing the "first character" optimization for patterns starting
+with \b or \B, though it was doing it for other lookbehind assertions. That is,
+it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
+the letter 'x'. On long subject strings, this gives a significant speed-up.
+
+
+Version 2.05 21-Apr-99
+----------------------
+
+1. Changed the type of magic_number from int to long int so that it works
+properly on 16-bit systems.
+
+2. Fixed a bug which caused patterns starting with .* not to work correctly
+when the subject string contained newline characters. PCRE was assuming
+anchoring for such patterns in all cases, which is not correct because .* will
+not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
+DOTALL is set at top level; otherwise it knows that patterns starting with .*
+must be retried after every newline in the subject.
+
+
+Version 2.04 18-Feb-99
+----------------------
+
+1. For parenthesized subpatterns with repeats whose minimum was zero, the
+computation of the store needed to hold the pattern was incorrect (too large).
+If such patterns were nested a few deep, this could multiply and become a real
+problem.
+
+2. Added /M option to pcretest to show the memory requirement of a specific
+pattern. Made -m a synonym of -s (which does this globally) for compatibility.
+
+3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
+compiled in such a way that the backtracking after subsequent failure was
+pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
+((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
+
+
+Version 2.03 02-Feb-99
+----------------------
+
+1. Fixed typo and small mistake in man page.
+
+2. Added 4th condition (GPL supersedes if conflict) and created separate
+LICENCE file containing the conditions.
+
+3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
+Perl, that is the internal \ allows the delimiter to be included in the
+pattern. Locked out the use of \ as a delimiter. If \ immediately follows
+the final delimiter, add \ to the end of the pattern (to test the error).
+
+4. Added the convenience functions for extracting substrings after a successful
+match. Updated pcretest to make it able to test these functions.
+
+
+Version 2.02 14-Jan-99
+----------------------
+
+1. Initialized the working variables associated with each extraction so that
+their saving and restoring doesn't refer to uninitialized store.
+
+2. Put dummy code into study.c in order to trick the optimizer of the IBM C
+compiler for OS/2 into generating correct code. Apparently IBM isn't going to
+fix the problem.
+
+3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
+calls, and wasn't printing the correct value for compiling calls. Increased the
+default value of LOOPREPEAT, and the number of significant figures in the
+times.
+
+4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
+
+5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
+a building problem on Windows NT with a FAT file system.
+
+
+Version 2.01 21-Oct-98
+----------------------
+
+1. Changed the API for pcre_compile() to allow for the provision of a pointer
+to character tables built by pcre_maketables() in the current locale. If NULL
+is passed, the default tables are used.
+
+
+Version 2.00 24-Sep-98
+----------------------
+
+1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
+it any more.
+
+2. Allow quantification of (?>) groups, and make it work correctly.
+
+3. The first character computation wasn't working for (?>) groups.
+
+4. Correct the implementation of \Z (it is permitted to match on the \n at the
+end of the subject) and add 5.005's \z, which really does match only at the
+very end of the subject.
+
+5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
+
+6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
+DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
+localized options. All options to pcre_study() were also removed.
+
+7. Add other new features from 5.005:
+
+   $(?<=           positive lookbehind
+   $(?<!           negative lookbehind
+   (?imsx-imsx)    added the unsetting capability
+                   such a setting is global if at outer level; local otherwise
+   (?imsx-imsx:)   non-capturing groups with option setting
+   (?(cond)re|re)  conditional pattern matching
+
+   A backreference to itself in a repeated group matches the previous
+   captured string.
+
+8. General tidying up of studying (both automatic and via "study")
+consequential on the addition of new assertions.
+
+9. As in 5.005, unlimited repeated groups that could match an empty substring
+are no longer faulted at compile time. Instead, the loop is forcibly broken at
+runtime if any iteration does actually match an empty substring.
+
+10. Include the RunTest script in the distribution.
+
+11. Added tests from the Perl 5.005_02 distribution. This showed up a few
+discrepancies, some of which were old and were also with respect to 5.004. They
+have now been fixed.
+
+
+Version 1.09 28-Apr-98
+----------------------
+
+1. A negated single character class followed by a quantifier with a minimum
+value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
+program crashes, or just wrong answers. This did not apply to negated classes
+containing more than one character, or to minima other than one.
+
+
+Version 1.08 27-Mar-98
+----------------------
+
+1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
+
+2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
+latter must appear before anything that relies on it in the pattern.
+
+
+Version 1.07 16-Feb-98
+----------------------
+
+1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
+repeat of a potentially empty string).
+
+
+Version 1.06 23-Jan-98
+----------------------
+
+1. Added Markus Oberhumer's little patches for C++.
+
+2. Literal strings longer than 255 characters were broken.
+
+
+Version 1.05 23-Dec-97
+----------------------
+
+1. Negated character classes containing more than one character were failing if
+PCRE_CASELESS was set at run time.
+
+
+Version 1.04 19-Dec-97
+----------------------
+
+1. Corrected the man page, where some "const" qualifiers had been omitted.
+
+2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
+input syntax.
+
+3. Fixed memory leak which occurred when a regex with back references was
+matched with an offsets vector that wasn't big enough. The temporary memory
+that is used in this case wasn't being freed if the match failed.
+
+4. Tidied pcretest to ensure it frees memory that it gets.
+
+5. Temporary memory was being obtained in the case where the passed offsets
+vector was exactly big enough.
+
+6. Corrected definition of offsetof() from change 5 below.
+
+7. I had screwed up change 6 below and broken the rules for the use of
+setjmp(). Now fixed.
+
+
+Version 1.03 18-Dec-97
+----------------------
+
+1. A erroneous regex with a missing opening parenthesis was correctly
+diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
+on some systems.
+
+2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
+it was reported that one broken compiler failed on the former because "code" is
+also an independent variable.
+
+3. The erroneous regex a[]b caused an array overrun reference.
+
+4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
+fail on data ending with that character. (It was going on too far, and checking
+the next character, typically a binary zero.) This was specific to the
+optimized code for single-character negative classes.
+
+5. Added a contributed patch from the TIN world which does the following:
+
+  + Add an undef for memmove, in case the the system defines a macro for it.
+
+  + Add a definition of offsetof(), in case there isn't one. (I don't know
+    the reason behind this - offsetof() is part of the ANSI standard - but
+    it does no harm).
+
+  + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
+    most of the places where whitespace preceded '#'. I have given up and
+    allowed the remaining 2 cases to be at the margin.
+
+  + Rename some variables in pcre to eliminate shadowing. This seems very
+    pedantic, but does no harm, of course.
+
+6. Moved the call to setjmp() into its own function, to get rid of warnings
+from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
+
+7. Constructs such as \d{8,} were compiling into the equivalent of
+\d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
+outcome, but in this particular case used more store than had been allocated,
+which caused the bug to be discovered because it threw up an internal error.
+
+8. The debugging code in both pcre and pcretest for outputting the compiled
+form of a regex was going wrong in the case of back references followed by
+curly-bracketed repeats.
+
+
+Version 1.02 12-Dec-97
+----------------------
+
+1. Typos in pcre.3 and comments in the source fixed.
+
+2. Applied a contributed patch to get rid of places where it used to remove
+'const' from variables, and fixed some signed/unsigned and uninitialized
+variable warnings.
+
+3. Added the "runtest" target to Makefile.
+
+4. Set default compiler flag to -O2 rather than just -O.
+
+
+Version 1.01 19-Nov-97
+----------------------
+
+1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
+like /([ab]*)*/, that is, for classes with more than one character in them.
+
+2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
+as /((?>a*))*/ (a PCRE_EXTRA facility).
+
+
+Version 1.00 18-Nov-97
+----------------------
+
+1. Added compile-time macros to support systems such as SunOS4 which don't have
+memmove() or strerror() but have other things that can be used instead.
+
+2. Arranged that "make clean" removes the executables.
+
+
+Version 0.99 27-Oct-97
+----------------------
+
+1. Fixed bug in code for optimizing classes with only one character. It was
+initializing a 32-byte map regardless, which could cause it to run off the end
+of the memory it had got.
+
+2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
+
+
+Version 0.98 22-Oct-97
+----------------------
+
+1. Fixed bug in code for handling temporary memory usage when there are more
+back references than supplied space in the ovector. This could cause segfaults.
+
+
+Version 0.97 21-Oct-97
+----------------------
+
+1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
+
+2. Optimized negated single characters not to use a bit map.
+
+3. Brought error texts together as macro definitions; clarified some of them;
+fixed one that was wrong - it said "range out of order" when it meant "invalid
+escape sequence".
+
+4. Changed some char * arguments to const char *.
+
+5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
+
+6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
+pcretest.
+
+
+Version 0.96 16-Oct-97
+----------------------
+
+1. Added a simple "pgrep" utility to the distribution.
+
+2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
+unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
+where "ddd" means "one or more decimal digits".
+
+3. Fixed serious bug. If a pattern had a back reference, but the call to
+pcre_exec() didn't supply a large enough ovector to record the related
+identifying subpattern, the match always failed. PCRE now remembers the number
+of the largest back reference, and gets some temporary memory in which to save
+the offsets during matching if necessary, in order to ensure that
+backreferences always work.
+
+4. Increased the compatibility with Perl in a number of ways:
+
+  (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
+      to request this handling. The option can be set at compile or exec time.
+
+  (b) $ matches before a terminating newline by default; an option
+      PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
+      mode). The option can be set at compile or exec time.
+
+  (c) The handling of \ followed by a digit other than 0 is now supposed to be
+      the same as Perl's. If the decimal number it represents is less than 10
+      or there aren't that many previous left capturing parentheses, an octal
+      escape is read. Inside a character class, it's always an octal escape,
+      even if it is a single digit.
+
+  (d) An escaped but undefined alphabetic character is taken as a literal,
+      unless PCRE_EXTRA is set. Currently this just reserves the remaining
+      escapes.
+
+  (e) {0} is now permitted. (The previous item is removed from the compiled
+      pattern).
+
+5. Changed all the names of code files so that the basic parts are no longer
+than 10 characters, and abolished the teeny "globals.c" file.
+
+6. Changed the handling of character classes; they are now done with a 32-byte
+bit map always.
+
+7. Added the -d and /D options to pcretest to make it possible to look at the
+internals of compilation without having to recompile pcre.
+
+
+Version 0.95 23-Sep-97
+----------------------
+
+1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
+\x20 at the start of a run of normal characters. These were being treated as
+real characters, instead of the source characters being re-checked.
+
+
+Version 0.94 18-Sep-97
+----------------------
+
+1. The functions are now thread-safe, with the caveat that the global variables
+containing pointers to malloc() and free() or alternative functions are the
+same for all threads.
+
+2. Get pcre_study() to generate a bitmap of initial characters for non-
+anchored patterns when this is possible, and use it if passed to pcre_exec().
+
+
+Version 0.93 15-Sep-97
+----------------------
+
+1. /(b)|(:+)/ was computing an incorrect first character.
+
+2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
+but not actually doing anything yet.
+
+3. Treat "-" characters in classes that cannot be part of ranges as literals,
+as Perl does (e.g. [-az] or [az-]).
+
+4. Set the anchored flag if a branch starts with .* or .*? because that tests
+all possible positions.
+
+5. Split up into different modules to avoid including unneeded functions in a
+compiled binary. However, compile and exec are still in one module. The "study"
+function is split off.
+
+6. The character tables are now in a separate module whose source is generated
+by an auxiliary program - but can then be edited by hand if required. There are
+now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
+toupper() in the code.
+
+7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
+make them global. Abolish the function for setting them, as the caller can now
+set them directly.
+
+
+Version 0.92 11-Sep-97
+----------------------
+
+1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
+(e.g. /a{1,3}/) was broken (I mis-optimized it).
+
+2. Caseless matching was not working in character classes if the characters in
+the pattern were in upper case.
+
+3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
+
+4. Make PCRE_ANCHORED public and accept as a compile option.
+
+5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
+PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
+pass them.
+
+6. Give an error if bad option bits passed at compile or run time.
+
+7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
+pcretest to cause it to pass that flag.
+
+8. Add pcre_info(), to get the number of identifying subpatterns, the stored
+options, and the first character, if set.
+
+9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
+
+
+Version 0.91 10-Sep-97
+----------------------
+
+1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
+match the empty string as in /(a*)*/. It was looping and ultimately crashing.
+
+2. PCRE was looping on encountering an indefinitely repeated back reference to
+a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
+Perl does - treats the match as successful.
+
+****