glib inlined into SameTime

git-svn-id: http://svn.miranda-ng.org/main/trunk@8685 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c

1 files changed, 2785 insertions, 0 deletions

diff --git a/protocols/Sametime/src/glib/gmarkup.c b/protocols/Sametime/src/glib/gmarkup.c
new file mode 100644
index 0000000000..1ad1ba8b2f
--- /dev/null
+++ b/protocols/Sametime/src/glib/gmarkup.c
@@ -0,0 +1,2785 @@
+/* gmarkup.c - Simple XML-like parser
+ *
+ *  Copyright 2000, 2003 Red Hat, Inc.
+ *  Copyright 2007, 2008 Ryan Lortie <desrt@desrt.ca>
+ *
+ * GLib is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GLib; see the file COPYING.LIB.  If not,
+ * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ *   Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include "gmarkup.h"
+
+#include "galloca.h"
+#include "gstrfuncs.h"
+#include "gstring.h"
+#include "gtestutils.h"
+#include "glibintl.h"
+
+GQuark
+g_markup_error_quark (void)
+{
+  return g_quark_from_static_string ("g-markup-error-quark");
+}
+
+typedef enum
+{
+  STATE_START,
+  STATE_AFTER_OPEN_ANGLE,
+  STATE_AFTER_CLOSE_ANGLE,
+  STATE_AFTER_ELISION_SLASH, /* the slash that obviates need for end element */
+  STATE_INSIDE_OPEN_TAG_NAME,
+  STATE_INSIDE_ATTRIBUTE_NAME,
+  STATE_AFTER_ATTRIBUTE_NAME,
+  STATE_BETWEEN_ATTRIBUTES,
+  STATE_AFTER_ATTRIBUTE_EQUALS_SIGN,
+  STATE_INSIDE_ATTRIBUTE_VALUE_SQ,
+  STATE_INSIDE_ATTRIBUTE_VALUE_DQ,
+  STATE_INSIDE_TEXT,
+  STATE_AFTER_CLOSE_TAG_SLASH,
+  STATE_INSIDE_CLOSE_TAG_NAME,
+  STATE_AFTER_CLOSE_TAG_NAME,
+  STATE_INSIDE_PASSTHROUGH,
+  STATE_ERROR
+} GMarkupParseState;
+
+typedef struct
+{
+  const char *prev_element;
+  const GMarkupParser *prev_parser;
+  gpointer prev_user_data;
+} GMarkupRecursionTracker;
+
+struct _GMarkupParseContext
+{
+  const GMarkupParser *parser;
+
+  GMarkupParseFlags flags;
+
+  gint line_number;
+  gint char_number;
+
+  gpointer user_data;
+  GDestroyNotify dnotify;
+
+  /* A piece of character data or an element that
+   * hasn't "ended" yet so we haven't yet called
+   * the callback for it.
+   */
+  GString *partial_chunk;
+  GSList *spare_chunks;
+
+  GMarkupParseState state;
+  GSList *tag_stack;
+  GSList *tag_stack_gstr;
+  GSList *spare_list_nodes;
+
+  GString **attr_names;
+  GString **attr_values;
+  gint cur_attr;
+  gint alloc_attrs;
+
+  const gchar *current_text;
+  gssize       current_text_len;      
+  const gchar *current_text_end;
+
+  /* used to save the start of the last interesting thingy */
+  const gchar *start;
+
+  const gchar *iter;
+
+  guint document_empty : 1;
+  guint parsing : 1;
+  guint awaiting_pop : 1;
+  gint balance;
+
+  /* subparser support */
+  GSList *subparser_stack; /* (GMarkupRecursionTracker *) */
+  const char *subparser_element;
+  gpointer held_user_data;
+};
+
+/*
+ * Helpers to reduce our allocation overhead, we have
+ * a well defined allocation lifecycle.
+ */
+static GSList *
+get_list_node (GMarkupParseContext *context, gpointer data)
+{
+  GSList *node;
+  if (context->spare_list_nodes != NULL)
+    {
+      node = context->spare_list_nodes;
+      context->spare_list_nodes = g_slist_remove_link (context->spare_list_nodes, node);
+    }
+  else
+    node = g_slist_alloc();
+  node->data = data;
+  return node;
+}
+
+static void
+free_list_node (GMarkupParseContext *context, GSList *node)
+{
+  node->data = NULL;
+  context->spare_list_nodes = g_slist_concat (node, context->spare_list_nodes);
+}
+
+static inline void
+string_blank (GString *string)
+{
+  string->str[0] = '\0';
+  string->len = 0;
+}
+
+/**
+ * g_markup_parse_context_new:
+ * @parser: a #GMarkupParser
+ * @flags: one or more #GMarkupParseFlags
+ * @user_data: user data to pass to #GMarkupParser functions
+ * @user_data_dnotify: user data destroy notifier called when the parse context is freed
+ * 
+ * Creates a new parse context. A parse context is used to parse
+ * marked-up documents. You can feed any number of documents into
+ * a context, as long as no errors occur; once an error occurs,
+ * the parse context can't continue to parse text (you have to free it
+ * and create a new parse context).
+ * 
+ * Return value: a new #GMarkupParseContext
+ **/
+GMarkupParseContext *
+g_markup_parse_context_new (const GMarkupParser *parser,
+                            GMarkupParseFlags    flags,
+                            gpointer             user_data,
+                            GDestroyNotify       user_data_dnotify)
+{
+  GMarkupParseContext *context;
+
+  g_return_val_if_fail (parser != NULL, NULL);
+
+  context = g_new (GMarkupParseContext, 1);
+
+  context->parser = parser;
+  context->flags = flags;
+  context->user_data = user_data;
+  context->dnotify = user_data_dnotify;
+
+  context->line_number = 1;
+  context->char_number = 1;
+
+  context->partial_chunk = NULL;
+  context->spare_chunks = NULL;
+  context->spare_list_nodes = NULL;
+
+  context->state = STATE_START;
+  context->tag_stack = NULL;
+  context->tag_stack_gstr = NULL;
+  context->attr_names = NULL;
+  context->attr_values = NULL;
+  context->cur_attr = -1;
+  context->alloc_attrs = 0;
+
+  context->current_text = NULL;
+  context->current_text_len = -1;
+  context->current_text_end = NULL;
+
+  context->start = NULL;
+  context->iter = NULL;
+
+  context->document_empty = TRUE;
+  context->parsing = FALSE;
+
+  context->awaiting_pop = FALSE;
+  context->subparser_stack = NULL;
+  context->subparser_element = NULL;
+
+  /* this is only looked at if awaiting_pop = TRUE.  initialise anyway. */
+  context->held_user_data = NULL;
+
+  context->balance = 0;
+
+  return context;
+}
+
+static void
+string_full_free (gpointer ptr, gpointer user_data)
+{
+  g_string_free (ptr, TRUE);
+}
+
+static void clear_attributes (GMarkupParseContext *context);
+
+/**
+ * g_markup_parse_context_free:
+ * @context: a #GMarkupParseContext
+ * 
+ * Frees a #GMarkupParseContext. Can't be called from inside
+ * one of the #GMarkupParser functions. Can't be called while
+ * a subparser is pushed.
+ **/
+void
+g_markup_parse_context_free (GMarkupParseContext *context)
+{
+  g_return_if_fail (context != NULL);
+  g_return_if_fail (!context->parsing);
+  g_return_if_fail (!context->subparser_stack);
+  g_return_if_fail (!context->awaiting_pop);
+
+  if (context->dnotify)
+    (* context->dnotify) (context->user_data);
+
+  clear_attributes (context);
+  g_free (context->attr_names);
+  g_free (context->attr_values);
+
+  g_slist_foreach (context->tag_stack_gstr, string_full_free, NULL);
+  g_slist_free (context->tag_stack_gstr);
+  g_slist_free (context->tag_stack);
+
+  g_slist_foreach (context->spare_chunks, string_full_free, NULL);
+  g_slist_free (context->spare_chunks);
+  g_slist_free (context->spare_list_nodes);
+
+  if (context->partial_chunk)
+    g_string_free (context->partial_chunk, TRUE);
+
+  g_free (context);
+}
+
+static void pop_subparser_stack (GMarkupParseContext *context);
+
+static void
+mark_error (GMarkupParseContext *context,
+            GError              *error)
+{
+  context->state = STATE_ERROR;
+
+  if (context->parser->error)
+    (*context->parser->error) (context, error, context->user_data);
+
+  /* report the error all the way up to free all the user-data */
+  while (context->subparser_stack)
+    {
+      pop_subparser_stack (context);
+      context->awaiting_pop = FALSE; /* already been freed */
+
+      if (context->parser->error)
+        (*context->parser->error) (context, error, context->user_data);
+    }
+}
+
+static void set_error (GMarkupParseContext *context,
+           	       GError             **error,
+           	       GMarkupError         code,
+           	       const gchar         *format,
+           	       ...) G_GNUC_PRINTF (4, 5);
+
+static void
+set_error_literal (GMarkupParseContext *context,
+                   GError             **error,
+                   GMarkupError         code,
+                   const gchar         *message)
+{
+  GError *tmp_error;
+
+  tmp_error = g_error_new_literal (G_MARKUP_ERROR, code, message);
+
+  g_prefix_error (&tmp_error,
+                  _("Error on line %d char %d: "),
+                  context->line_number,
+                  context->char_number);
+
+  mark_error (context, tmp_error);
+
+  g_propagate_error (error, tmp_error);
+}
+
+static void
+set_error (GMarkupParseContext *context,
+           GError             **error,
+           GMarkupError         code,
+           const gchar         *format,
+           ...)
+{
+  gchar *s;
+  gchar *s_valid;
+  va_list args;
+
+  va_start (args, format);
+  s = g_strdup_vprintf (format, args);
+  va_end (args);
+
+  /* Make sure that the GError message is valid UTF-8 even if it is
+   * complaining about invalid UTF-8 in the markup: */
+  s_valid = _g_utf8_make_valid (s);
+  set_error_literal (context, error, code, s);
+
+  g_free (s);
+  g_free (s_valid);
+}
+
+static void
+propagate_error (GMarkupParseContext  *context,
+                 GError              **dest,
+                 GError               *src)
+{
+  if (context->flags & G_MARKUP_PREFIX_ERROR_POSITION)
+    g_prefix_error (&src,
+                    _("Error on line %d char %d: "),
+                    context->line_number,
+                    context->char_number);
+
+  mark_error (context, src);
+
+  g_propagate_error (dest, src);
+}
+
+#define IS_COMMON_NAME_END_CHAR(c) \
+  ((c) == '=' || (c) == '/' || (c) == '>' || (c) == ' ')
+
+static gboolean
+slow_name_validate (GMarkupParseContext *context, const char *name, GError **error)
+{
+  const char *p = name;
+
+  if (!g_utf8_validate (name, strlen (name), NULL))
+    {
+      set_error (context, error, G_MARKUP_ERROR_BAD_UTF8,
+		 _("Invalid UTF-8 encoded text in name - not valid '%s'"), name);
+      return FALSE;
+    }
+
+  if (!(g_ascii_isalpha (*p) ||
+	(!IS_COMMON_NAME_END_CHAR (*p) &&
+	 (*p == '_' || 
+	  *p == ':' ||
+	  g_unichar_isalpha (g_utf8_get_char (p))))))
+    {
+      set_error (context, error, G_MARKUP_ERROR_PARSE,
+		 _("'%s' is not a valid name "), name);
+      return FALSE;
+    }
+
+  for (p = g_utf8_next_char (name); *p != '\0'; p = g_utf8_next_char (p))
+    {
+      /* is_name_char */
+      if (!(g_ascii_isalnum (*p) ||
+	    (!IS_COMMON_NAME_END_CHAR (*p) &&
+	     (*p == '.' || 
+	      *p == '-' ||
+	      *p == '_' ||
+	      *p == ':' ||
+	      g_unichar_isalpha (g_utf8_get_char (p))))))
+	{
+	  set_error (context, error, G_MARKUP_ERROR_PARSE,
+		     _("'%s' is not a valid name: '%c' "), name, *p);
+	  return FALSE;
+	}
+    }
+  return TRUE;
+}
+
+/* 
+ * Use me for elements, attributes etc.
+ */
+static gboolean
+name_validate (GMarkupParseContext *context, const char *name, GError **error)
+{
+  char mask;
+  const char *p;
+
+  /* name start char */
+  p = name;
+  if (G_UNLIKELY (IS_COMMON_NAME_END_CHAR (*p) ||
+		  !(g_ascii_isalpha (*p) || *p == '_' || *p == ':')))
+    goto slow_validate;
+  
+  for (mask = *p++; *p != '\0'; p++)
+    {
+      mask |= *p;
+
+      /* is_name_char */
+      if (G_UNLIKELY (!(g_ascii_isalnum (*p) ||
+			(!IS_COMMON_NAME_END_CHAR (*p) &&
+			 (*p == '.' || 
+			  *p == '-' ||
+			  *p == '_' ||
+			  *p == ':')))))
+	goto slow_validate;
+    }
+
+  if (mask & 0x80) /* un-common / non-ascii */
+    goto slow_validate;
+
+  return TRUE;
+
+ slow_validate:
+  return slow_name_validate (context, name, error);
+}
+
+static gboolean
+text_validate (GMarkupParseContext *context, const char *p, int len, GError **error)
+{
+  if (!g_utf8_validate (p, len, NULL))
+    {
+      set_error (context, error, G_MARKUP_ERROR_BAD_UTF8,
+		 _("Invalid UTF-8 encoded text in name - not valid '%s'"), p);
+      return FALSE;
+    }
+  else
+    return TRUE;
+}
+
+static gchar*
+char_str (gunichar c,
+          gchar   *buf)
+{
+  memset (buf, 0, 8);
+  g_unichar_to_utf8 (c, buf);
+  return buf;
+}
+
+static gchar*
+utf8_str (const gchar *utf8,
+          gchar       *buf)
+{
+  char_str (g_utf8_get_char (utf8), buf);
+  return buf;
+}
+
+static void
+set_unescape_error (GMarkupParseContext *context,
+                    GError             **error,
+                    const gchar         *remaining_text,
+                    GMarkupError         code,
+                    const gchar         *format,
+                    ...)
+{
+  GError *tmp_error;
+  gchar *s;
+  va_list args;
+  gint remaining_newlines;
+  const gchar *p;
+
+  remaining_newlines = 0;
+  p = remaining_text;
+  while (*p != '\0')
+    {
+      if (*p == '\n')
+        ++remaining_newlines;
+      ++p;
+    }
+
+  va_start (args, format);
+  s = g_strdup_vprintf (format, args);
+  va_end (args);
+
+  tmp_error = g_error_new (G_MARKUP_ERROR,
+                           code,
+                           _("Error on line %d: %s"),
+                           context->line_number - remaining_newlines,
+                           s);
+
+  g_free (s);
+
+  mark_error (context, tmp_error);
+
+  g_propagate_error (error, tmp_error);
+}
+
+/*
+ * re-write the GString in-place, unescaping anything that escaped.
+ * most XML does not contain entities, or escaping.
+ */
+static gboolean
+unescape_gstring_inplace (GMarkupParseContext *context,
+			  GString             *string,
+			  gboolean            *is_ascii,
+			  GError             **error)
+{
+  char mask, *to;
+  int line_num = 1;
+  const char *from;
+  gboolean normalize_attribute;
+
+  *is_ascii = FALSE;
+
+  /* are we unescaping an attribute or not ? */
+  if (context->state == STATE_INSIDE_ATTRIBUTE_VALUE_SQ ||
+      context->state == STATE_INSIDE_ATTRIBUTE_VALUE_DQ)
+    normalize_attribute = TRUE;
+  else
+    normalize_attribute = FALSE;
+
+  /*
+   * Meeks' theorum: unescaping can only shrink text.
+   * for &lt; etc. this is obvious, for &#xffff; more
+   * thought is required, but this is patently so.
+   */
+  mask = 0;
+  for (from = to = string->str; *from != '\0'; from++, to++) 
+    {
+      *to = *from;
+
+      mask |= *to;
+      if (*to == '\n')
+	line_num++;
+      if (normalize_attribute && (*to == '\t' || *to == '\n'))
+	*to = ' ';
+      if (*to == '\r')
+	{
+	  *to = normalize_attribute ? ' ' : '\n';
+	  if (from[1] == '\n')
+	    from++;
+	}
+      if (*from == '&')
+	{
+	  from++;
+	  if (*from == '#')
+	    {
+	      gboolean is_hex = FALSE;
+	      gulong l;
+	      gchar *end = NULL;
+
+	      from++;
+
+	      if (*from == 'x')
+		{
+		  is_hex = TRUE;
+		  from++;
+		}
+
+	      /* digit is between start and p */
+	      errno = 0;
+	      if (is_hex)
+		l = strtoul (from, &end, 16);
+	      else
+		l = strtoul (from, &end, 10);
+	      
+	      if (end == from || errno != 0)
+		{
+		  set_unescape_error (context, error,
+				      from, G_MARKUP_ERROR_PARSE,
+				      _("Failed to parse '%-.*s', which "
+					"should have been a digit "
+					"inside a character reference "
+					"(&#234; for example) - perhaps "
+					"the digit is too large"),
+				      end - from, from);
+		  return FALSE;
+		}
+	      else if (*end != ';')
+		{
+		  set_unescape_error (context, error,
+				      from, G_MARKUP_ERROR_PARSE,
+				      _("Character reference did not end with a "
+					"semicolon; "
+					"most likely you used an ampersand "
+					"character without intending to start "
+					"an entity - escape ampersand as &amp;"));
+		  return FALSE;
+		}
+	      else
+		{
+		  /* characters XML 1.1 permits */
+		  if ((0 < l && l <= 0xD7FF) ||
+		      (0xE000 <= l && l <= 0xFFFD) ||
+		      (0x10000 <= l && l <= 0x10FFFF))
+		    {
+		      gchar buf[8];
+		      char_str (l, buf);
+		      strcpy (to, buf);
+		      to += strlen (buf) - 1;
+		      from = end;
+		      if (l >= 0x80) /* not ascii */
+			mask |= 0x80;
+		    }
+		  else
+		    {
+		      set_unescape_error (context, error,
+					  from, G_MARKUP_ERROR_PARSE,
+					  _("Character reference '%-.*s' does not "
+					    "encode a permitted character"),
+					  end - from, from);
+		      return FALSE;
+		    }
+		}
+            }
+
+          else if (strncmp (from, "lt;", 3) == 0)
+	    {
+	      *to = '<';
+	      from += 2;
+	    }
+          else if (strncmp (from, "gt;", 3) == 0)
+	    {
+	      *to = '>';
+	      from += 2;
+	    }
+          else if (strncmp (from, "amp;", 4) == 0)
+	    {
+	      *to = '&';
+	      from += 3;
+	    }
+          else if (strncmp (from, "quot;", 5) == 0)
+	    {
+	      *to = '"';
+	      from += 4;
+	    }
+	  else if (strncmp (from, "apos;", 5) == 0)
+	    {
+	      *to = '\'';
+	      from += 4;
+	    }
+	  else
+	    {
+	      if (*from == ';')
+		set_unescape_error (context, error,
+				    from, G_MARKUP_ERROR_PARSE,
+				    _("Empty entity '&;' seen; valid "
+				      "entities are: &amp; &quot; &lt; &gt; &apos;"));
+	      else
+		{
+		  const char *end = strchr (from, ';');
+		  if (end)
+		    set_unescape_error (context, error,
+					from, G_MARKUP_ERROR_PARSE,
+					_("Entity name '%-.*s' is not known"),
+					end-from, from);
+		  else
+		    set_unescape_error (context, error,
+					from, G_MARKUP_ERROR_PARSE,
+					_("Entity did not end with a semicolon; "
+					  "most likely you used an ampersand "
+					  "character without intending to start "
+					  "an entity - escape ampersand as &amp;"));
+			}
+			return FALSE;
+	  }
+	}
+	 }
+
+  g_assert (to - string->str <= string->len);
+  if (to - string->str != string->len)
+    g_string_truncate (string, to - string->str);
+
+  *is_ascii = !(mask & 0x80);
+
+  return TRUE;
+}
+
+static inline gboolean
+advance_char (GMarkupParseContext *context)
+{  
+  context->iter++;
+  context->char_number++;
+
+  if (G_UNLIKELY (context->iter == context->current_text_end))
+      return FALSE;
+
+  else if (G_UNLIKELY (*context->iter == '\n'))
+    {
+      context->line_number++;
+      context->char_number = 1;
+    }
+  
+  return TRUE;
+}
+
+static inline gboolean
+xml_isspace (char c)
+{
+  return c == ' ' || c == '\t' || c == '\n' || c == '\r';
+}
+
+static void
+skip_spaces (GMarkupParseContext *context)
+{
+  do
+    {
+      if (!xml_isspace (*context->iter))
+        return;
+    }
+  while (advance_char (context));
+}
+
+static void
+advance_to_name_end (GMarkupParseContext *context)
+{
+  do
+    {
+      if (IS_COMMON_NAME_END_CHAR (*(context->iter)))
+        return;
+      if (xml_isspace (*(context->iter)))
+	return;
+    }
+  while (advance_char (context));
+}
+
+static void
+release_chunk (GMarkupParseContext *context, GString *str)
+{
+  GSList *node;
+  if (!str)
+    return;
+  if (str->allocated_len > 256)
+    { /* large strings are unusual and worth freeing */
+      g_string_free (str, TRUE);
+      return;
+    }
+  string_blank (str);
+  node = get_list_node (context, str);
+  context->spare_chunks = g_slist_concat (node, context->spare_chunks);
+}
+
+static void
+add_to_partial (GMarkupParseContext *context,
+                const gchar         *text_start,
+                const gchar         *text_end)
+{
+  if (context->partial_chunk == NULL)
+    { /* allocate a new chunk to parse into */
+
+      if (context->spare_chunks != NULL)
+	{
+	  GSList *node = context->spare_chunks;
+	  context->spare_chunks = g_slist_remove_link (context->spare_chunks, node);
+	  context->partial_chunk = node->data;
+	  free_list_node (context, node);
+	}
+      else
+	context->partial_chunk = g_string_sized_new (MAX (28, text_end - text_start));
+    }
+
+  if (text_start != text_end)
+    g_string_insert_len (context->partial_chunk, -1,
+			 text_start, text_end - text_start);
+}
+
+static inline void
+truncate_partial (GMarkupParseContext *context)
+{
+  if (context->partial_chunk != NULL)
+    string_blank (context->partial_chunk);
+}
+
+static inline const gchar*
+current_element (GMarkupParseContext *context)
+{
+  return context->tag_stack->data;
+}
+
+static void
+pop_subparser_stack (GMarkupParseContext *context)
+{
+  GMarkupRecursionTracker *tracker;
+
+  g_assert (context->subparser_stack);
+
+  tracker = context->subparser_stack->data;
+
+  context->awaiting_pop = TRUE;
+  context->held_user_data = context->user_data;
+
+  context->user_data = tracker->prev_user_data;
+  context->parser = tracker->prev_parser;
+  context->subparser_element = tracker->prev_element;
+  g_slice_free (GMarkupRecursionTracker, tracker);
+
+  context->subparser_stack = g_slist_delete_link (context->subparser_stack,
+                                                  context->subparser_stack);
+}
+
+static void
+push_partial_as_tag (GMarkupParseContext *context)
+{
+  GString *str = context->partial_chunk;
+  /* sadly, this is exported by gmarkup_get_element_stack as-is */
+  context->tag_stack = g_slist_concat (get_list_node (context, str->str), context->tag_stack);
+  context->tag_stack_gstr = g_slist_concat (get_list_node (context, str), context->tag_stack_gstr);
+  context->partial_chunk = NULL;
+}
+
+static void
+pop_tag (GMarkupParseContext *context)
+{
+  GSList *nodea, *nodeb;
+
+  nodea = context->tag_stack;
+  nodeb = context->tag_stack_gstr;
+  release_chunk (context, nodeb->data);
+  context->tag_stack = g_slist_remove_link (context->tag_stack, nodea);
+  context->tag_stack_gstr = g_slist_remove_link (context->tag_stack_gstr, nodeb);
+  free_list_node (context, nodea);
+  free_list_node (context, nodeb);
+}
+
+static void
+possibly_finish_subparser (GMarkupParseContext *context)
+{
+  if (current_element (context) == context->subparser_element)
+    pop_subparser_stack (context);
+}
+
+static void
+ensure_no_outstanding_subparser (GMarkupParseContext *context)
+{
+  if (context->awaiting_pop)
+    g_critical ("During the first end_element call after invoking a "
+		"subparser you must pop the subparser stack and handle "
+		"the freeing of the subparser user_data.  This can be "
+		"done by calling the end function of the subparser.  "
+		"Very probably, your program just leaked memory.");
+
+  /* let valgrind watch the pointer disappear... */
+  context->held_user_data = NULL;
+  context->awaiting_pop = FALSE;
+}
+
+static const gchar*
+current_attribute (GMarkupParseContext *context)
+{
+  g_assert (context->cur_attr >= 0);
+  return context->attr_names[context->cur_attr]->str;
+}
+
+static void
+add_attribute (GMarkupParseContext *context, GString *str)
+{
+  if (context->cur_attr + 2 >= context->alloc_attrs)
+    {
+      context->alloc_attrs += 5; /* silly magic number */
+      context->attr_names = g_realloc (context->attr_names, sizeof(GString*)*context->alloc_attrs);
+      context->attr_values = g_realloc (context->attr_values, sizeof(GString*)*context->alloc_attrs);
+    }
+  context->cur_attr++;
+  context->attr_names[context->cur_attr] = str;
+  context->attr_values[context->cur_attr] = NULL;
+  context->attr_names[context->cur_attr+1] = NULL;
+  context->attr_values[context->cur_attr+1] = NULL;
+}
+
+static void
+clear_attributes (GMarkupParseContext *context)
+{
+  /* Go ahead and free the attributes. */
+  for (; context->cur_attr >= 0; context->cur_attr--)
+    {
+      int pos = context->cur_attr;
+      release_chunk (context, context->attr_names[pos]);
+      release_chunk (context, context->attr_values[pos]);
+      context->attr_names[pos] = context->attr_values[pos] = NULL;
+    }
+  g_assert (context->cur_attr == -1);
+  g_assert (context->attr_names == NULL ||
+	    context->attr_names[0] == NULL);
+  g_assert (context->attr_values == NULL ||
+	    context->attr_values[0] == NULL);
+}
+
+/* This has to be a separate function to ensure the alloca's
+   are unwound on exit - otherwise we grow & blow the stack
+   with large documents */
+static inline void
+emit_start_element (GMarkupParseContext *context, GError **error)
+{
+  int i;
+  const gchar *start_name;
+  const gchar **attr_names;
+  const gchar **attr_values;
+  GError *tmp_error;
+  
+  attr_names = g_newa (const gchar *, context->cur_attr + 2);
+  attr_values = g_newa (const gchar *, context->cur_attr + 2);
+  for (i = 0; i < context->cur_attr + 1; i++)
+    {
+      attr_names[i] = context->attr_names[i]->str;
+      attr_values[i] = context->attr_values[i]->str;
+    }
+  attr_names[i] = NULL;
+  attr_values[i] = NULL;
+  
+  /* Call user callback for element start */
+  tmp_error = NULL;
+  start_name = current_element (context);
+  
+  if (context->parser->start_element &&
+      name_validate (context, start_name, error))
+    (* context->parser->start_element) (context,
+					start_name,
+					(const gchar **)attr_names,
+					(const gchar **)attr_values,
+					context->user_data,
+					&tmp_error);
+  clear_attributes (context);
+  
+  if (tmp_error != NULL)
+    propagate_error (context, error, tmp_error);
+}
+
+/**
+ * g_markup_parse_context_parse:
+ * @context: a #GMarkupParseContext
+ * @text: chunk of text to parse
+ * @text_len: length of @text in bytes
+ * @error: return location for a #GError
+ * 
+ * Feed some data to the #GMarkupParseContext. The data need not
+ * be valid UTF-8; an error will be signaled if it's invalid.
+ * The data need not be an entire document; you can feed a document
+ * into the parser incrementally, via multiple calls to this function.
+ * Typically, as you receive data from a network connection or file,
+ * you feed each received chunk of data into this function, aborting
+ * the process if an error occurs. Once an error is reported, no further
+ * data may be fed to the #GMarkupParseContext; all errors are fatal.
+ * 
+ * Return value: %FALSE if an error occurred, %TRUE on success
+ **/
+gboolean
+g_markup_parse_context_parse (GMarkupParseContext *context,
+                              const gchar         *text,
+                              gssize               text_len,
+                              GError             **error)
+{
+  g_return_val_if_fail (context != NULL, FALSE);
+  g_return_val_if_fail (text != NULL, FALSE);
+  g_return_val_if_fail (context->state != STATE_ERROR, FALSE);
+  g_return_val_if_fail (!context->parsing, FALSE);
+  
+  if (text_len < 0)
+    text_len = strlen (text);
+
+  if (text_len == 0)
+    return TRUE;
+  
+  context->parsing = TRUE;
+  
+
+  context->current_text = text;
+  context->current_text_len = text_len;
+  context->current_text_end = context->current_text + text_len;
+  context->iter = context->current_text;
+  context->start = context->iter;
+
+  if (context->current_text_len == 0)
+    goto finished;
+
+  while (context->iter != context->current_text_end)
+    {
+      switch (context->state)
+        {
+        case STATE_START:
+          /* Possible next state: AFTER_OPEN_ANGLE */
+
+          g_assert (context->tag_stack == NULL);
+
+          /* whitespace is ignored outside of any elements */
+          skip_spaces (context);
+
+          if (context->iter != context->current_text_end)
+            {
+              if (*context->iter == '<')
+                {
+                  /* Move after the open angle */
+                  advance_char (context);
+
+                  context->state = STATE_AFTER_OPEN_ANGLE;
+
+                  /* this could start a passthrough */
+                  context->start = context->iter;
+
+                  /* document is now non-empty */
+                  context->document_empty = FALSE;
+                }
+              else
+                {
+                  set_error_literal (context,
+                                     error,
+                                     G_MARKUP_ERROR_PARSE,
+                                     _("Document must begin with an element (e.g. <book>)"));
+                }
+            }
+          break;
+
+        case STATE_AFTER_OPEN_ANGLE:
+          /* Possible next states: INSIDE_OPEN_TAG_NAME,
+           *  AFTER_CLOSE_TAG_SLASH, INSIDE_PASSTHROUGH
+           */
+          if (*context->iter == '?' ||
+              *context->iter == '!')
+            {
+              /* include < in the passthrough */
+              const gchar *openangle = "<";
+              add_to_partial (context, openangle, openangle + 1);
+              context->start = context->iter;
+	      context->balance = 1;
+              context->state = STATE_INSIDE_PASSTHROUGH;
+            }
+          else if (*context->iter == '/')
+            {
+              /* move after it */
+              advance_char (context);
+
+              context->state = STATE_AFTER_CLOSE_TAG_SLASH;
+            }
+          else if (!IS_COMMON_NAME_END_CHAR (*(context->iter)))
+            {
+              context->state = STATE_INSIDE_OPEN_TAG_NAME;
+
+              /* start of tag name */
+              context->start = context->iter;
+            }
+          else
+            {
+              gchar buf[8];
+
+              set_error (context,
+                         error,
+                         G_MARKUP_ERROR_PARSE,
+                         _("'%s' is not a valid character following "
+                           "a '<' character; it may not begin an "
+                           "element name"),
+                         utf8_str (context->iter, buf));
+            }
+          break;
+
+          /* The AFTER_CLOSE_ANGLE state is actually sort of
+           * broken, because it doesn't correspond to a range
+           * of characters in the input stream as the others do,
+           * and thus makes things harder to conceptualize
+           */
+        case STATE_AFTER_CLOSE_ANGLE:
+          /* Possible next states: INSIDE_TEXT, STATE_START */
+          if (context->tag_stack == NULL)
+            {
+              context->start = NULL;
+              context->state = STATE_START;
+            }
+          else
+            {
+              context->start = context->iter;
+              context->state = STATE_INSIDE_TEXT;
+            }
+          break;
+
+        case STATE_AFTER_ELISION_SLASH:
+          /* Possible next state: AFTER_CLOSE_ANGLE */
+
+          {
+            /* We need to pop the tag stack and call the end_element
+             * function, since this is the close tag
+             */
+            GError *tmp_error = NULL;
+          
+            g_assert (context->tag_stack != NULL);
+
+            possibly_finish_subparser (context);
+
+            tmp_error = NULL;
+            if (context->parser->end_element)
+              (* context->parser->end_element) (context,
+						current_element (context),
+                                                context->user_data,
+                                                &tmp_error);
+
+            ensure_no_outstanding_subparser (context);
+          
+            if (tmp_error)
+              {
+                mark_error (context, tmp_error);
+                g_propagate_error (error, tmp_error);
+              }          
+            else
+              {
+                if (*context->iter == '>')
+                  {
+                    /* move after the close angle */
+                    advance_char (context);
+                    context->state = STATE_AFTER_CLOSE_ANGLE;
+                  }
+                else
+                  {
+                    gchar buf[8];
+
+                    set_error (context,
+                               error,
+                               G_MARKUP_ERROR_PARSE,
+                               _("Odd character '%s', expected a '>' character "
+                                 "to end the empty-element tag '%s'"),
+                               utf8_str (context->iter, buf),
+                               current_element (context));
+                  }
+              }
+	    pop_tag (context);
+          }
+          break;
+
+        case STATE_INSIDE_OPEN_TAG_NAME:
+          /* Possible next states: BETWEEN_ATTRIBUTES */
+
+          /* if there's a partial chunk then it's the first part of the
+           * tag name. If there's a context->start then it's the start
+           * of the tag name in current_text, the partial chunk goes
+           * before that start though.
+           */
+          advance_to_name_end (context);
+
+          if (context->iter == context->current_text_end)
+            {
+              /* The name hasn't necessarily ended. Merge with
+               * partial chunk, leave state unchanged.
+               */
+              add_to_partial (context, context->start, context->iter);
+            }
+          else
+            {
+              /* The name has ended. Combine it with the partial chunk
+               * if any; push it on the stack; enter next state.
+               */
+              add_to_partial (context, context->start, context->iter);
+	      push_partial_as_tag (context);
+
+              context->state = STATE_BETWEEN_ATTRIBUTES;
+              context->start = NULL;
+            }
+          break;
+
+        case STATE_INSIDE_ATTRIBUTE_NAME:
+          /* Possible next states: AFTER_ATTRIBUTE_NAME */
+
+          advance_to_name_end (context);
+	  add_to_partial (context, context->start, context->iter);
+
+          /* read the full name, if we enter the equals sign state
+           * then add the attribute to the list (without the value),
+           * otherwise store a partial chunk to be prepended later.
+           */
+          if (context->iter != context->current_text_end)
+	    context->state = STATE_AFTER_ATTRIBUTE_NAME;
+	  break;
+
+	case STATE_AFTER_ATTRIBUTE_NAME:
+          /* Possible next states: AFTER_ATTRIBUTE_EQUALS_SIGN */
+
+	  skip_spaces (context);
+
+	  if (context->iter != context->current_text_end)
+	    {
+	      /* The name has ended. Combine it with the partial chunk
+	       * if any; push it on the stack; enter next state.
+	       */
+	      if (!name_validate (context, context->partial_chunk->str, error))
+		break;
+
+	      add_attribute (context, context->partial_chunk);
+	      
+              context->partial_chunk = NULL;
+              context->start = NULL;
+	      
+              if (*context->iter == '=')
+                {
+                  advance_char (context);
+                  context->state = STATE_AFTER_ATTRIBUTE_EQUALS_SIGN;
+                }
+              else
+                {
+                  gchar buf[8];
+
+                  set_error (context,
+                             error,
+                             G_MARKUP_ERROR_PARSE,
+                             _("Odd character '%s', expected a '=' after "
+                               "attribute name '%s' of element '%s'"),
+                             utf8_str (context->iter, buf),
+                             current_attribute (context),
+                             current_element (context));
+		  
+                }
+            }
+          break;
+
+        case STATE_BETWEEN_ATTRIBUTES:
+          /* Possible next states: AFTER_CLOSE_ANGLE,
+           * AFTER_ELISION_SLASH, INSIDE_ATTRIBUTE_NAME
+           */
+          skip_spaces (context);
+
+          if (context->iter != context->current_text_end)
+            {
+              if (*context->iter == '/')
+                {
+                  advance_char (context);
+                  context->state = STATE_AFTER_ELISION_SLASH;
+                }
+              else if (*context->iter == '>')
+                {
+                  advance_char (context);
+                  context->state = STATE_AFTER_CLOSE_ANGLE;
+                }
+              else if (!IS_COMMON_NAME_END_CHAR (*(context->iter)))
+                {
+                  context->state = STATE_INSIDE_ATTRIBUTE_NAME;
+                  /* start of attribute name */
+                  context->start = context->iter;
+                }
+              else
+                {
+                  gchar buf[8];
+
+                  set_error (context,
+                             error,
+                             G_MARKUP_ERROR_PARSE,
+                             _("Odd character '%s', expected a '>' or '/' "
+                               "character to end the start tag of "
+                               "element '%s', or optionally an attribute; "
+                               "perhaps you used an invalid character in "
+                               "an attribute name"),
+                             utf8_str (context->iter, buf),
+                             current_element (context));
+                }
+
+              /* If we're done with attributes, invoke
+               * the start_element callback
+               */
+              if (context->state == STATE_AFTER_ELISION_SLASH ||
+                  context->state == STATE_AFTER_CLOSE_ANGLE)
+		emit_start_element (context, error);
+            }
+          break;
+
+        case STATE_AFTER_ATTRIBUTE_EQUALS_SIGN:
+          /* Possible next state: INSIDE_ATTRIBUTE_VALUE_[SQ/DQ] */
+
+	  skip_spaces (context);
+
+	  if (context->iter != context->current_text_end)
+	    {
+	      if (*context->iter == '"')
+		{
+		  advance_char (context);
+		  context->state = STATE_INSIDE_ATTRIBUTE_VALUE_DQ;
+		  context->start = context->iter;
+		}
+	      else if (*context->iter == '\'')
+		{
+		  advance_char (context);
+		  context->state = STATE_INSIDE_ATTRIBUTE_VALUE_SQ;
+		  context->start = context->iter;
+		}
+	      else
+		{
+		  gchar buf[8];
+		  
+		  set_error (context,
+			     error,
+			     G_MARKUP_ERROR_PARSE,
+			     _("Odd character '%s', expected an open quote mark "
+			       "after the equals sign when giving value for "
+			       "attribute '%s' of element '%s'"),
+			     utf8_str (context->iter, buf),
+			     current_attribute (context),
+			     current_element (context));
+		}
+	    }
+          break;
+
+        case STATE_INSIDE_ATTRIBUTE_VALUE_SQ:
+        case STATE_INSIDE_ATTRIBUTE_VALUE_DQ:
+          /* Possible next states: BETWEEN_ATTRIBUTES */
+	  {
+	    gchar delim;
+
+	    if (context->state == STATE_INSIDE_ATTRIBUTE_VALUE_SQ) 
+	      {
+		delim = '\'';
+	      }
+	    else 
+	      {
+		delim = '"';
+	      }
+
+	    do
+	      {
+		if (*context->iter == delim)
+		  break;
+	      }
+	    while (advance_char (context));
+	  }
+          if (context->iter == context->current_text_end)
+            {
+              /* The value hasn't necessarily ended. Merge with
+               * partial chunk, leave state unchanged.
+               */
+              add_to_partial (context, context->start, context->iter);
+            }
+          else
+            {
+	      gboolean is_ascii;
+              /* The value has ended at the quote mark. Combine it
+               * with the partial chunk if any; set it for the current
+               * attribute.
+               */
+              add_to_partial (context, context->start, context->iter);
+
+              g_assert (context->cur_attr >= 0);
+              
+              if (unescape_gstring_inplace (context, context->partial_chunk, &is_ascii, error) &&
+		  (is_ascii || text_validate (context, context->partial_chunk->str,
+					      context->partial_chunk->len, error)))
+                {
+                  /* success, advance past quote and set state. */
+                  context->attr_values[context->cur_attr] = context->partial_chunk;
+		  context->partial_chunk = NULL;
+                  advance_char (context);
+                  context->state = STATE_BETWEEN_ATTRIBUTES;
+                  context->start = NULL;
+                }
+              
+              truncate_partial (context);
+            }
+          break;
+
+        case STATE_INSIDE_TEXT:
+          /* Possible next states: AFTER_OPEN_ANGLE */
+          do
+            {
+              if (*context->iter == '<')
+                break;
+            }
+          while (advance_char (context));
+
+          /* The text hasn't necessarily ended. Merge with
+           * partial chunk, leave state unchanged.
+           */
+
+          add_to_partial (context, context->start, context->iter);
+
+          if (context->iter != context->current_text_end)
+            {
+	      gboolean is_ascii;
+
+              /* The text has ended at the open angle. Call the text
+               * callback.
+               */
+              
+              if (unescape_gstring_inplace (context, context->partial_chunk, &is_ascii, error) &&
+		  (is_ascii || text_validate (context, context->partial_chunk->str,
+					      context->partial_chunk->len, error)))
+                {
+                  GError *tmp_error = NULL;
+
+                  if (context->parser->text)
+                    (*context->parser->text) (context,
+					      context->partial_chunk->str,
+					      context->partial_chunk->len,
+                                              context->user_data,
+                                              &tmp_error);
+                  
+                  if (tmp_error == NULL)
+                    {
+                      /* advance past open angle and set state. */
+                      advance_char (context);
+                      context->state = STATE_AFTER_OPEN_ANGLE;
+                      /* could begin a passthrough */
+                      context->start = context->iter;
+                    }
+                  else
+                    propagate_error (context, error, tmp_error);
+                }
+
+              truncate_partial (context);
+            }
+          break;
+
+        case STATE_AFTER_CLOSE_TAG_SLASH:
+          /* Possible next state: INSIDE_CLOSE_TAG_NAME */
+          if (!IS_COMMON_NAME_END_CHAR (*(context->iter)))
+            {
+              context->state = STATE_INSIDE_CLOSE_TAG_NAME;
+
+              /* start of tag name */
+              context->start = context->iter;
+            }
+          else
+            {
+              gchar buf[8];
+
+              set_error (context,
+                         error,
+                         G_MARKUP_ERROR_PARSE,
+                         _("'%s' is not a valid character following "
+                           "the characters '</'; '%s' may not begin an "
+                           "element name"),
+                         utf8_str (context->iter, buf),
+                         utf8_str (context->iter, buf));
+            }
+          break;
+
+        case STATE_INSIDE_CLOSE_TAG_NAME:
+          /* Possible next state: AFTER_CLOSE_TAG_NAME */
+          advance_to_name_end (context);
+	  add_to_partial (context, context->start, context->iter);
+
+          if (context->iter != context->current_text_end)
+	    context->state = STATE_AFTER_CLOSE_TAG_NAME;
+	  break;
+
+	case STATE_AFTER_CLOSE_TAG_NAME:
+          /* Possible next state: AFTER_CLOSE_TAG_SLASH */
+
+	  skip_spaces (context);
+	  
+	  if (context->iter != context->current_text_end)
+	    {
+	      GString *close_name;
+
+	      close_name = context->partial_chunk;
+	      context->partial_chunk = NULL;
+              
+	      if (*context->iter != '>')
+		{
+		  gchar buf[8];
+
+		  set_error (context,
+			     error,
+			     G_MARKUP_ERROR_PARSE,
+			     _("'%s' is not a valid character following "
+			       "the close element name '%s'; the allowed "
+			       "character is '>'"),
+			     utf8_str (context->iter, buf),
+			     close_name->str);
+		}
+	      else if (context->tag_stack == NULL)
+		{
+		  set_error (context,
+			     error,
+			     G_MARKUP_ERROR_PARSE,
+			     _("Element '%s' was closed, no element "
+			       "is currently open"),
+			     close_name->str);
+		}
+	      else if (strcmp (close_name->str, current_element (context)) != 0)
+		{
+		  set_error (context,
+			     error,
+			     G_MARKUP_ERROR_PARSE,
+			     _("Element '%s' was closed, but the currently "
+			       "open element is '%s'"),
+			     close_name->str,
+			     current_element (context));
+		}
+	      else
+		{
+		  GError *tmp_error;
+		  advance_char (context);
+		  context->state = STATE_AFTER_CLOSE_ANGLE;
+		  context->start = NULL;
+		  
+                  possibly_finish_subparser (context);
+
+		  /* call the end_element callback */
+		  tmp_error = NULL;
+		  if (context->parser->end_element)
+		    (* context->parser->end_element) (context,
+						      close_name->str,
+						      context->user_data,
+						      &tmp_error);
+		  
+                  ensure_no_outstanding_subparser (context);
+		  pop_tag (context);
+		  
+		  if (tmp_error)
+                    propagate_error (context, error, tmp_error);
+                }
+	      context->partial_chunk = close_name;
+	      truncate_partial (context);
+            }
+          break;
+	  
+        case STATE_INSIDE_PASSTHROUGH:
+          /* Possible next state: AFTER_CLOSE_ANGLE */
+          do
+            {
+	      if (*context->iter == '<') 
+		context->balance++;
+              if (*context->iter == '>') 
+		{				
+		  gchar *str;
+		  gsize len;
+
+		  context->balance--;
+		  add_to_partial (context, context->start, context->iter);
+		  context->start = context->iter;
+
+		  str = context->partial_chunk->str;
+		  len = context->partial_chunk->len;
+
+		  if (str[1] == '?' && str[len - 1] == '?')
+		    break;
+		  if (strncmp (str, "<!--", 4) == 0 && 
+		      strcmp (str + len - 2, "--") == 0)
+		    break;
+		  if (strncmp (str, "<![CDATA[", 9) == 0 && 
+		      strcmp (str + len - 2, "]]") == 0)
+		    break;
+		  if (strncmp (str, "<!DOCTYPE", 9) == 0 &&
+		      context->balance == 0)
+		    break;
+		}
+            }
+          while (advance_char (context));
+
+          if (context->iter == context->current_text_end)
+            {
+              /* The passthrough hasn't necessarily ended. Merge with
+               * partial chunk, leave state unchanged.
+               */
+               add_to_partial (context, context->start, context->iter);
+            }
+          else
+            {
+              /* The passthrough has ended at the close angle. Combine
+               * it with the partial chunk if any. Call the passthrough
+               * callback. Note that the open/close angles are
+               * included in the text of the passthrough.
+               */
+              GError *tmp_error = NULL;
+
+              advance_char (context); /* advance past close angle */
+              add_to_partial (context, context->start, context->iter);
+
+	      if (context->flags & G_MARKUP_TREAT_CDATA_AS_TEXT &&
+		  strncmp (context->partial_chunk->str, "<![CDATA[", 9) == 0)
+		{
+		  if (context->parser->text &&
+		      text_validate (context,
+				     context->partial_chunk->str + 9,
+				     context->partial_chunk->len - 12,
+				     error))
+		    (*context->parser->text) (context,
+					      context->partial_chunk->str + 9,
+					      context->partial_chunk->len - 12,
+					      context->user_data,
+					      &tmp_error);
+		}
+	      else if (context->parser->passthrough &&
+		       text_validate (context,
+				      context->partial_chunk->str,
+				      context->partial_chunk->len,
+				      error))
+                (*context->parser->passthrough) (context,
+                                                 context->partial_chunk->str,
+                                                 context->partial_chunk->len,
+                                                 context->user_data,
+                                                 &tmp_error);
+                  
+              truncate_partial (context);
+
+              if (tmp_error == NULL)
+                {
+                  context->state = STATE_AFTER_CLOSE_ANGLE;
+                  context->start = context->iter; /* could begin text */
+                }
+              else
+                propagate_error (context, error, tmp_error);
+            }
+          break;
+
+        case STATE_ERROR:
+          goto finished;
+          break;
+
+        default:
+          g_assert_not_reached ();
+          break;
+        }
+    }
+
+ finished:
+  context->parsing = FALSE;
+
+  return context->state != STATE_ERROR;
+}
+
+/**
+ * g_markup_parse_context_end_parse:
+ * @context: a #GMarkupParseContext
+ * @error: return location for a #GError
+ * 
+ * Signals to the #GMarkupParseContext that all data has been
+ * fed into the parse context with g_markup_parse_context_parse().
+ * This function reports an error if the document isn't complete,
+ * for example if elements are still open.
+ * 
+ * Return value: %TRUE on success, %FALSE if an error was set
+ **/
+gboolean
+g_markup_parse_context_end_parse (GMarkupParseContext *context,
+                                  GError             **error)
+{
+  g_return_val_if_fail (context != NULL, FALSE);
+  g_return_val_if_fail (!context->parsing, FALSE);
+  g_return_val_if_fail (context->state != STATE_ERROR, FALSE);
+
+  if (context->partial_chunk != NULL)
+    {
+      g_string_free (context->partial_chunk, TRUE);
+      context->partial_chunk = NULL;
+    }
+
+  if (context->document_empty)
+    {
+      set_error_literal (context, error, G_MARKUP_ERROR_EMPTY,
+                         _("Document was empty or contained only whitespace"));
+      return FALSE;
+    }
+  
+  context->parsing = TRUE;
+  
+  switch (context->state)
+    {
+    case STATE_START:
+      /* Nothing to do */
+      break;
+
+    case STATE_AFTER_OPEN_ANGLE:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly just after an open angle bracket '<'"));
+      break;
+
+    case STATE_AFTER_CLOSE_ANGLE:
+      if (context->tag_stack != NULL)
+        {
+          /* Error message the same as for INSIDE_TEXT */
+          set_error (context, error, G_MARKUP_ERROR_PARSE,
+                     _("Document ended unexpectedly with elements still open - "
+                       "'%s' was the last element opened"),
+                     current_element (context));
+        }
+      break;
+      
+    case STATE_AFTER_ELISION_SLASH:
+      set_error (context, error, G_MARKUP_ERROR_PARSE,
+                 _("Document ended unexpectedly, expected to see a close angle "
+                   "bracket ending the tag <%s/>"), current_element (context));
+      break;
+
+    case STATE_INSIDE_OPEN_TAG_NAME:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly inside an element name"));
+      break;
+
+    case STATE_INSIDE_ATTRIBUTE_NAME:
+    case STATE_AFTER_ATTRIBUTE_NAME:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly inside an attribute name"));
+      break;
+
+    case STATE_BETWEEN_ATTRIBUTES:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly inside an element-opening "
+                           "tag."));
+      break;
+
+    case STATE_AFTER_ATTRIBUTE_EQUALS_SIGN:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly after the equals sign "
+                           "following an attribute name; no attribute value"));
+      break;
+
+    case STATE_INSIDE_ATTRIBUTE_VALUE_SQ:
+    case STATE_INSIDE_ATTRIBUTE_VALUE_DQ:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly while inside an attribute "
+                           "value"));
+      break;
+
+    case STATE_INSIDE_TEXT:
+      g_assert (context->tag_stack != NULL);
+      set_error (context, error, G_MARKUP_ERROR_PARSE,
+                 _("Document ended unexpectedly with elements still open - "
+                   "'%s' was the last element opened"),
+                 current_element (context));
+      break;
+
+    case STATE_AFTER_CLOSE_TAG_SLASH:
+    case STATE_INSIDE_CLOSE_TAG_NAME:
+    case STATE_AFTER_CLOSE_TAG_NAME:
+      set_error (context, error, G_MARKUP_ERROR_PARSE,
+                 _("Document ended unexpectedly inside the close tag for "
+                   "element '%s'"), current_element (context));
+      break;
+
+    case STATE_INSIDE_PASSTHROUGH:
+      set_error_literal (context, error, G_MARKUP_ERROR_PARSE,
+                         _("Document ended unexpectedly inside a comment or "
+                           "processing instruction"));
+      break;
+
+    case STATE_ERROR:
+    default:
+      g_assert_not_reached ();
+      break;
+    }
+
+  context->parsing = FALSE;
+
+  return context->state != STATE_ERROR;
+}
+
+/**
+ * g_markup_parse_context_get_element:
+ * @context: a #GMarkupParseContext
+ * @returns: the name of the currently open element, or %NULL
+ *
+ * Retrieves the name of the currently open element.
+ *
+ * If called from the start_element or end_element handlers this will
+ * give the element_name as passed to those functions. For the parent
+ * elements, see g_markup_parse_context_get_element_stack().
+ *
+ * Since: 2.2
+ **/
+G_CONST_RETURN gchar *
+g_markup_parse_context_get_element (GMarkupParseContext *context)
+{
+  g_return_val_if_fail (context != NULL, NULL);
+
+  if (context->tag_stack == NULL) 
+    return NULL;
+  else
+    return current_element (context);
+} 
+
+/**
+ * g_markup_parse_context_get_element_stack:
+ * @context: a #GMarkupParseContext
+ *
+ * Retrieves the element stack from the internal state of the parser.
+ * The returned #GSList is a list of strings where the first item is
+ * the currently open tag (as would be returned by
+ * g_markup_parse_context_get_element()) and the next item is its
+ * immediate parent.
+ *
+ * This function is intended to be used in the start_element and
+ * end_element handlers where g_markup_parse_context_get_element()
+ * would merely return the name of the element that is being
+ * processed.
+ *
+ * Returns: the element stack, which must not be modified
+ *
+ * Since: 2.16
+ **/
+G_CONST_RETURN GSList *
+g_markup_parse_context_get_element_stack (GMarkupParseContext *context)
+{
+  g_return_val_if_fail (context != NULL, NULL);
+  return context->tag_stack;
+}
+
+/**
+ * g_markup_parse_context_get_position:
+ * @context: a #GMarkupParseContext
+ * @line_number: return location for a line number, or %NULL
+ * @char_number: return location for a char-on-line number, or %NULL
+ *
+ * Retrieves the current line number and the number of the character on
+ * that line. Intended for use in error messages; there are no strict
+ * semantics for what constitutes the "current" line number other than
+ * "the best number we could come up with for error messages."
+ * 
+ **/
+void
+g_markup_parse_context_get_position (GMarkupParseContext *context,
+                                     gint                *line_number,
+                                     gint                *char_number)
+{
+  g_return_if_fail (context != NULL);
+
+  if (line_number)
+    *line_number = context->line_number;
+
+  if (char_number)
+    *char_number = context->char_number;
+}
+
+/**
+ * g_markup_parse_context_get_user_data:
+ * @context: a #GMarkupParseContext
+ *
+ * Returns the user_data associated with @context.  This will either
+ * be the user_data that was provided to g_markup_parse_context_new()
+ * or to the most recent call of g_markup_parse_context_push().
+ *
+ * Returns: the provided user_data. The returned data belongs to
+ *     the markup context and will be freed when g_markup_context_free()
+ *     is called.
+ *
+ * Since: 2.18
+ **/
+gpointer
+g_markup_parse_context_get_user_data (GMarkupParseContext *context)
+{
+  return context->user_data;
+}
+
+/**
+ * g_markup_parse_context_push:
+ * @context: a #GMarkupParseContext
+ * @parser: a #GMarkupParser
+ * @user_data: user data to pass to #GMarkupParser functions
+ *
+ * Temporarily redirects markup data to a sub-parser.
+ *
+ * This function may only be called from the start_element handler of
+ * a #GMarkupParser.  It must be matched with a corresponding call to
+ * g_markup_parse_context_pop() in the matching end_element handler
+ * (except in the case that the parser aborts due to an error).
+ *
+ * All tags, text and other data between the matching tags is
+ * redirected to the subparser given by @parser.  @user_data is used
+ * as the user_data for that parser.  @user_data is also passed to the
+ * error callback in the event that an error occurs.  This includes
+ * errors that occur in subparsers of the subparser.
+ *
+ * The end tag matching the start tag for which this call was made is
+ * handled by the previous parser (which is given its own user_data)
+ * which is why g_markup_parse_context_pop() is provided to allow "one
+ * last access" to the @user_data provided to this function.  In the
+ * case of error, the @user_data provided here is passed directly to
+ * the error callback of the subparser and g_markup_parse_context()
+ * should not be called.  In either case, if @user_data was allocated
+ * then it ought to be freed from both of these locations.
+ *
+ * This function is not intended to be directly called by users
+ * interested in invoking subparsers.  Instead, it is intended to be
+ * used by the subparsers themselves to implement a higher-level
+ * interface.
+ *
+ * As an example, see the following implementation of a simple
+ * parser that counts the number of tags encountered.
+ *
+ * |[
+ * typedef struct
+ * {
+ *   gint tag_count;
+ * } CounterData;
+ * 
+ * static void
+ * counter_start_element (GMarkupParseContext  *context,
+ *                        const gchar          *element_name,
+ *                        const gchar         **attribute_names,
+ *                        const gchar         **attribute_values,
+ *                        gpointer              user_data,
+ *                        GError              **error)
+ * {
+ *   CounterData *data = user_data;
+ * 
+ *   data->tag_count++;
+ * }
+ * 
+ * static void
+ * counter_error (GMarkupParseContext *context,
+ *                GError              *error,
+ *                gpointer             user_data)
+ * {
+ *   CounterData *data = user_data;
+ * 
+ *   g_slice_free (CounterData, data);
+ * }
+ * 
+ * static GMarkupParser counter_subparser =
+ * {
+ *   counter_start_element,
+ *   NULL,
+ *   NULL,
+ *   NULL,
+ *   counter_error
+ * };
+ * ]|
+ *
+ * In order to allow this parser to be easily used as a subparser, the
+ * following interface is provided:
+ *
+ * |[
+ * void
+ * start_counting (GMarkupParseContext *context)
+ * {
+ *   CounterData *data = g_slice_new (CounterData);
+ * 
+ *   data->tag_count = 0;
+ *   g_markup_parse_context_push (context, &counter_subparser, data);
+ * }
+ * 
+ * gint
+ * end_counting (GMarkupParseContext *context)
+ * {
+ *   CounterData *data = g_markup_parse_context_pop (context);
+ *   int result;
+ * 
+ *   result = data->tag_count;
+ *   g_slice_free (CounterData, data);
+ * 
+ *   return result;
+ * }
+ * ]|
+ *
+ * The subparser would then be used as follows:
+ *
+ * |[
+ * static void start_element (context, element_name, ...)
+ * {
+ *   if (strcmp (element_name, "count-these") == 0)
+ *     start_counting (context);
+ * 
+ *   /&ast; else, handle other tags... &ast;/
+ * }
+ * 
+ * static void end_element (context, element_name, ...)
+ * {
+ *   if (strcmp (element_name, "count-these") == 0)
+ *     g_print ("Counted %d tags\n", end_counting (context));
+ * 
+ *   /&ast; else, handle other tags... &ast;/
+ * }
+ * ]|
+ *
+ * Since: 2.18
+ **/
+void
+g_markup_parse_context_push (GMarkupParseContext *context,
+                             const GMarkupParser *parser,
+                             gpointer             user_data)
+{
+  GMarkupRecursionTracker *tracker;
+
+  tracker = g_slice_new (GMarkupRecursionTracker);
+  tracker->prev_element = context->subparser_element;
+  tracker->prev_parser = context->parser;
+  tracker->prev_user_data = context->user_data;
+
+  context->subparser_element = current_element (context);
+  context->parser = parser;
+  context->user_data = user_data;
+
+  context->subparser_stack = g_slist_prepend (context->subparser_stack,
+                                              tracker);
+}
+
+/**
+ * g_markup_parse_context_pop:
+ * @context: a #GMarkupParseContext
+ *
+ * Completes the process of a temporary sub-parser redirection.
+ *
+ * This function exists to collect the user_data allocated by a
+ * matching call to g_markup_parse_context_push().  It must be called
+ * in the end_element handler corresponding to the start_element
+ * handler during which g_markup_parse_context_push() was called.  You
+ * must not call this function from the error callback -- the
+ * @user_data is provided directly to the callback in that case.
+ *
+ * This function is not intended to be directly called by users
+ * interested in invoking subparsers.  Instead, it is intended to be
+ * used by the subparsers themselves to implement a higher-level
+ * interface.
+ *
+ * Returns: the user_data passed to g_markup_parse_context_push().
+ *
+ * Since: 2.18
+ **/
+gpointer
+g_markup_parse_context_pop (GMarkupParseContext *context)
+{
+  gpointer user_data;
+
+  if (!context->awaiting_pop)
+    possibly_finish_subparser (context);
+
+  g_assert (context->awaiting_pop);
+
+  context->awaiting_pop = FALSE;
+  
+  /* valgrind friendliness */
+  user_data = context->held_user_data;
+  context->held_user_data = NULL;
+
+  return user_data;
+}
+
+static void
+append_escaped_text (GString     *str,
+                     const gchar *text,
+                     gssize       length)    
+{
+  const gchar *p;
+  const gchar *end;
+  gunichar c;
+
+  p = text;
+  end = text + length;
+
+  while (p != end)
+    {
+      const gchar *next;
+      next = g_utf8_next_char (p);
+
+      switch (*p)
+        {
+        case '&':
+          g_string_append (str, "&amp;");
+          break;
+
+        case '<':
+          g_string_append (str, "&lt;");
+          break;
+
+        case '>':
+          g_string_append (str, "&gt;");
+          break;
+
+        case '\'':
+          g_string_append (str, "&apos;");
+          break;
+
+        case '"':
+          g_string_append (str, "&quot;");
+          break;
+
+        default:
+          c = g_utf8_get_char (p);
+          if ((0x1 <= c && c <= 0x8) ||
+              (0xb <= c && c  <= 0xc) ||
+              (0xe <= c && c <= 0x1f) ||
+              (0x7f <= c && c <= 0x84) ||
+              (0x86 <= c && c <= 0x9f))
+            g_string_append_printf (str, "&#x%x;", c);
+          else
+            g_string_append_len (str, p, next - p);
+          break;
+        }
+
+      p = next;
+    }
+}
+
+/**
+ * g_markup_escape_text:
+ * @text: some valid UTF-8 text
+ * @length: length of @text in bytes, or -1 if the text is nul-terminated
+ * 
+ * Escapes text so that the markup parser will parse it verbatim.
+ * Less than, greater than, ampersand, etc. are replaced with the
+ * corresponding entities. This function would typically be used
+ * when writing out a file to be parsed with the markup parser.
+ * 
+ * Note that this function doesn't protect whitespace and line endings
+ * from being processed according to the XML rules for normalization
+ * of line endings and attribute values.
+ *
+ * Note also that this function will produce character references in
+ * the range of &amp;#x1; ... &amp;#x1f; for all control sequences
+ * except for tabstop, newline and carriage return.  The character
+ * references in this range are not valid XML 1.0, but they are
+ * valid XML 1.1 and will be accepted by the GMarkup parser.
+ * 
+ * Return value: a newly allocated string with the escaped text
+ **/
+gchar*
+g_markup_escape_text (const gchar *text,
+                      gssize       length)  
+{
+  GString *str;
+
+  g_return_val_if_fail (text != NULL, NULL);
+
+  if (length < 0)
+    length = strlen (text);
+
+  /* prealloc at least as long as original text */
+  str = g_string_sized_new (length);
+  append_escaped_text (str, text, length);
+
+  return g_string_free (str, FALSE);
+}
+
+/**
+ * find_conversion:
+ * @format: a printf-style format string
+ * @after: location to store a pointer to the character after
+ *   the returned conversion. On a %NULL return, returns the
+ *   pointer to the trailing NUL in the string
+ * 
+ * Find the next conversion in a printf-style format string.
+ * Partially based on code from printf-parser.c,
+ * Copyright (C) 1999-2000, 2002-2003 Free Software Foundation, Inc.
+ * 
+ * Return value: pointer to the next conversion in @format,
+ *  or %NULL, if none.
+ **/
+static const char *
+find_conversion (const char  *format,
+		 const char **after)
+{
+  const char *start = format;
+  const char *cp;
+  
+  while (*start != '\0' && *start != '%')
+    start++;
+
+  if (*start == '\0')
+    {
+      *after = start;
+      return NULL;
+    }
+
+  cp = start + 1;
+
+  if (*cp == '\0')
+    {
+      *after = cp;
+      return NULL;
+    }
+  
+  /* Test for positional argument.  */
+  if (*cp >= '0' && *cp <= '9')
+    {
+      const char *np;
+      
+      for (np = cp; *np >= '0' && *np <= '9'; np++)
+	;
+      if (*np == '$')
+	cp = np + 1;
+    }
+
+  /* Skip the flags.  */
+  for (;;)
+    {
+      if (*cp == '\'' ||
+	  *cp == '-' ||
+	  *cp == '+' ||
+	  *cp == ' ' ||
+	  *cp == '#' ||
+	  *cp == '0')
+	cp++;
+      else
+	break;
+    }
+
+  /* Skip the field width.  */
+  if (*cp == '*')
+    {
+      cp++;
+
+      /* Test for positional argument.  */
+      if (*cp >= '0' && *cp <= '9')
+	{
+	  const char *np;
+
+	  for (np = cp; *np >= '0' && *np <= '9'; np++)
+	    ;
+	  if (*np == '$')
+	    cp = np + 1;
+	}
+    }
+  else
+    {
+      for (; *cp >= '0' && *cp <= '9'; cp++)
+	;
+    }
+
+  /* Skip the precision.  */
+  if (*cp == '.')
+    {
+      cp++;
+      if (*cp == '*')
+	{
+	  /* Test for positional argument.  */
+	  if (*cp >= '0' && *cp <= '9')
+	    {
+	      const char *np;
+
+	      for (np = cp; *np >= '0' && *np <= '9'; np++)
+		;
+	      if (*np == '$')
+		cp = np + 1;
+	    }
+	}
+      else
+	{
+	  for (; *cp >= '0' && *cp <= '9'; cp++)
+	    ;
+	}
+    }
+
+  /* Skip argument type/size specifiers.  */
+  while (*cp == 'h' ||
+	 *cp == 'L' ||
+	 *cp == 'l' ||
+	 *cp == 'j' ||
+	 *cp == 'z' ||
+	 *cp == 'Z' ||
+	 *cp == 't')
+    cp++;
+	  
+  /* Skip the conversion character.  */
+  cp++;
+
+  *after = cp;
+  return start;
+}
+
+/**
+ * g_markup_vprintf_escaped:
+ * @format: printf() style format string
+ * @args: variable argument list, similar to vprintf()
+ * 
+ * Formats the data in @args according to @format, escaping
+ * all string and character arguments in the fashion
+ * of g_markup_escape_text(). See g_markup_printf_escaped().
+ * 
+ * Return value: newly allocated result from formatting
+ *  operation. Free with g_free().
+ *
+ * Since: 2.4
+ **/
+char *
+g_markup_vprintf_escaped (const char *format,
+			  va_list     args)
+{
+  GString *format1;
+  GString *format2;
+  GString *result = NULL;
+  gchar *output1 = NULL;
+  gchar *output2 = NULL;
+  const char *p, *op1, *op2;
+  va_list args2;
+
+  /* The technique here, is that we make two format strings that
+   * have the identical conversions in the identical order to the
+   * original strings, but differ in the text in-between. We
+   * then use the normal g_strdup_vprintf() to format the arguments
+   * with the two new format strings. By comparing the results,
+   * we can figure out what segments of the output come from
+   * the the original format string, and what from the arguments,
+   * and thus know what portions of the string to escape.
+   *
+   * For instance, for:
+   *
+   *  g_markup_printf_escaped ("%s ate %d apples", "Susan & Fred", 5);
+   *
+   * We form the two format strings "%sX%dX" and %sY%sY". The results
+   * of formatting with those two strings are
+   *
+   * "%sX%dX" => "Susan & FredX5X"
+   * "%sY%dY" => "Susan & FredY5Y"
+   *
+   * To find the span of the first argument, we find the first position
+   * where the two arguments differ, which tells us that the first
+   * argument formatted to "Susan & Fred". We then escape that
+   * to "Susan &amp; Fred" and join up with the intermediate portions
+   * of the format string and the second argument to get
+   * "Susan &amp; Fred ate 5 apples".
+   */
+
+  /* Create the two modified format strings
+   */
+  format1 = g_string_new (NULL);
+  format2 = g_string_new (NULL);
+  p = format;
+  while (TRUE)
+    {
+      const char *after;
+      const char *conv = find_conversion (p, &after);
+      if (!conv)
+	break;
+
+      g_string_append_len (format1, conv, after - conv);
+      g_string_append_c (format1, 'X');
+      g_string_append_len (format2, conv, after - conv);
+      g_string_append_c (format2, 'Y');
+
+      p = after;
+    }
+
+  /* Use them to format the arguments
+   */
+  G_VA_COPY (args2, args);
+  
+  output1 = g_strdup_vprintf (format1->str, args);
+  if (!output1)
+    {
+      va_end (args2);
+      goto cleanup;
+    }
+  
+  output2 = g_strdup_vprintf (format2->str, args2);
+  va_end (args2);
+  if (!output2)
+    goto cleanup;
+
+  result = g_string_new (NULL);
+
+  /* Iterate through the original format string again,
+   * copying the non-conversion portions and the escaped
+   * converted arguments to the output string.
+   */
+  op1 = output1;
+  op2 = output2;
+  p = format;
+  while (TRUE)
+    {
+      const char *after;
+      const char *output_start;
+      const char *conv = find_conversion (p, &after);
+      char *escaped;
+      
+      if (!conv)	/* The end, after points to the trailing \0 */
+	{
+	  g_string_append_len (result, p, after - p);
+	  break;
+	}
+
+      g_string_append_len (result, p, conv - p);
+      output_start = op1;
+      while (*op1 == *op2)
+	{
+	  op1++;
+	  op2++;
+	}
+      
+      escaped = g_markup_escape_text (output_start, op1 - output_start);
+      g_string_append (result, escaped);
+      g_free (escaped);
+      
+      p = after;
+      op1++;
+      op2++;
+    }
+
+ cleanup:
+  g_string_free (format1, TRUE);
+  g_string_free (format2, TRUE);
+  g_free (output1);
+  g_free (output2);
+
+  if (result)
+    return g_string_free (result, FALSE);
+  else
+    return NULL;
+}
+
+/**
+ * g_markup_printf_escaped:
+ * @format: printf() style format string
+ * @Varargs: the arguments to insert in the format string
+ * 
+ * Formats arguments according to @format, escaping
+ * all string and character arguments in the fashion
+ * of g_markup_escape_text(). This is useful when you
+ * want to insert literal strings into XML-style markup
+ * output, without having to worry that the strings
+ * might themselves contain markup.
+ *
+ * |[
+ * const char *store = "Fortnum &amp; Mason";
+ * const char *item = "Tea";
+ * char *output;
+ * &nbsp;
+ * output = g_markup_printf_escaped ("&lt;purchase&gt;"
+ *                                   "&lt;store&gt;&percnt;s&lt;/store&gt;"
+ *                                   "&lt;item&gt;&percnt;s&lt;/item&gt;"
+ *                                   "&lt;/purchase&gt;",
+ *                                   store, item);
+ * ]|
+ * 
+ * Return value: newly allocated result from formatting
+ *  operation. Free with g_free().
+ *
+ * Since: 2.4
+ **/
+char *
+g_markup_printf_escaped (const char *format, ...)
+{
+  char *result;
+  va_list args;
+  
+  va_start (args, format);
+  result = g_markup_vprintf_escaped (format, args);
+  va_end (args);
+
+  return result;
+}
+
+static gboolean
+g_markup_parse_boolean (const char  *string,
+                        gboolean    *value)
+{
+  char const * const falses[] = { "false", "f", "no", "n", "0" };
+  char const * const trues[] = { "true", "t", "yes", "y", "1" };
+  int i;
+
+  for (i = 0; i < G_N_ELEMENTS (falses); i++)
+    {
+      if (g_ascii_strcasecmp (string, falses[i]) == 0)
+        {
+          if (value != NULL)
+            *value = FALSE;
+
+          return TRUE;
+        }
+    }
+
+  for (i = 0; i < G_N_ELEMENTS (trues); i++)
+    {
+      if (g_ascii_strcasecmp (string, trues[i]) == 0)
+        {
+          if (value != NULL)
+            *value = TRUE;
+
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
+/**
+ * GMarkupCollectType:
+ * @G_MARKUP_COLLECT_INVALID: used to terminate the list of attributes
+ *                            to collect.
+ * @G_MARKUP_COLLECT_STRING: collect the string pointer directly from
+ *                           the attribute_values[] array.  Expects a
+ *                           parameter of type (const char **).  If
+ *                           %G_MARKUP_COLLECT_OPTIONAL is specified
+ *                           and the attribute isn't present then the
+ *                           pointer will be set to %NULL.
+ * @G_MARKUP_COLLECT_STRDUP: as with %G_MARKUP_COLLECT_STRING, but
+ *                           expects a parameter of type (char **) and
+ *                           g_strdup()s the returned pointer.  The
+ *                           pointer must be freed with g_free().
+ * @G_MARKUP_COLLECT_BOOLEAN: expects a parameter of type (gboolean *)
+ *                            and parses the attribute value as a
+ *                            boolean.  Sets %FALSE if the attribute
+ *                            isn't present.  Valid boolean values
+ *                            consist of (case insensitive) "false",
+ *                            "f", "no", "n", "0" and "true", "t",
+ *                            "yes", "y", "1".
+ * @G_MARKUP_COLLECT_TRISTATE: as with %G_MARKUP_COLLECT_BOOLEAN, but
+ *                             in the case of a missing attribute a
+ *                             value is set that compares equal to
+ *                             neither %FALSE nor %TRUE.
+ *                             G_MARKUP_COLLECT_OPTIONAL is implied.
+ * @G_MARKUP_COLLECT_OPTIONAL: can be bitwise ORed with the other
+ *                             fields.  If present, allows the
+ *                             attribute not to appear.  A default
+ *                             value is set depending on what value
+ *                             type is used.
+ *
+ * A mixed enumerated type and flags field.  You must specify one type
+ * (string, strdup, boolean, tristate).  Additionally, you may
+ * optionally bitwise OR the type with the flag
+ * %G_MARKUP_COLLECT_OPTIONAL.
+ *
+ * It is likely that this enum will be extended in the future to
+ * support other types.
+ **/
+
+/**
+ * g_markup_collect_attributes:
+ * @element_name: the current tag name
+ * @attribute_names: the attribute names
+ * @attribute_values: the attribute values
+ * @error: a pointer to a #GError or %NULL
+ * @first_type: the #GMarkupCollectType of the
+ *              first attribute
+ * @first_attr: the name of the first attribute
+ * @...: a pointer to the storage location of the
+ *       first attribute (or %NULL), followed by
+ *       more types names and pointers, ending
+ *       with %G_MARKUP_COLLECT_INVALID.
+ * 
+ * Collects the attributes of the element from the
+ * data passed to the #GMarkupParser start_element
+ * function, dealing with common error conditions
+ * and supporting boolean values.
+ *
+ * This utility function is not required to write
+ * a parser but can save a lot of typing.
+ *
+ * The @element_name, @attribute_names,
+ * @attribute_values and @error parameters passed
+ * to the start_element callback should be passed
+ * unmodified to this function.
+ *
+ * Following these arguments is a list of
+ * "supported" attributes to collect.  It is an
+ * error to specify multiple attributes with the
+ * same name.  If any attribute not in the list
+ * appears in the @attribute_names array then an
+ * unknown attribute error will result.
+ *
+ * The #GMarkupCollectType field allows specifying
+ * the type of collection to perform and if a
+ * given attribute must appear or is optional.
+ *
+ * The attribute name is simply the name of the
+ * attribute to collect.
+ *
+ * The pointer should be of the appropriate type
+ * (see the descriptions under
+ * #GMarkupCollectType) and may be %NULL in case a
+ * particular attribute is to be allowed but
+ * ignored.
+ *
+ * This function deals with issuing errors for missing attributes 
+ * (of type %G_MARKUP_ERROR_MISSING_ATTRIBUTE), unknown attributes 
+ * (of type %G_MARKUP_ERROR_UNKNOWN_ATTRIBUTE) and duplicate 
+ * attributes (of type %G_MARKUP_ERROR_INVALID_CONTENT) as well 
+ * as parse errors for boolean-valued attributes (again of type
+ * %G_MARKUP_ERROR_INVALID_CONTENT). In all of these cases %FALSE 
+ * will be returned and @error will be set as appropriate.
+ *
+ * Return value: %TRUE if successful
+ *
+ * Since: 2.16
+ **/
+gboolean
+g_markup_collect_attributes (const gchar         *element_name,
+                             const gchar        **attribute_names,
+                             const gchar        **attribute_values,
+                             GError             **error,
+                             GMarkupCollectType   first_type,
+                             const gchar         *first_attr,
+                             ...)
+{
+  GMarkupCollectType type;
+  const gchar *attr;
+  guint64 collected;
+  int written;
+  va_list ap;
+  int i;
+
+  type = first_type;
+  attr = first_attr;
+  collected = 0;
+  written = 0;
+
+  va_start (ap, first_attr);
+  while (type != G_MARKUP_COLLECT_INVALID)
+    {
+      gboolean mandatory;
+      const gchar *value;
+
+      mandatory = !(type & G_MARKUP_COLLECT_OPTIONAL);
+      type &= (G_MARKUP_COLLECT_OPTIONAL - 1);
+
+      /* tristate records a value != TRUE and != FALSE
+       * for the case where the attribute is missing
+       */
+      if (type == G_MARKUP_COLLECT_TRISTATE)
+        mandatory = FALSE;
+
+      for (i = 0; attribute_names[i]; i++)
+        if (i >= 40 || !(collected & (G_GUINT64_CONSTANT(1) << i)))
+          if (!strcmp (attribute_names[i], attr))
+            break;
+
+      /* ISO C99 only promises that the user can pass up to 127 arguments.
+       * Subtracting the first 4 arguments plus the final NULL and dividing
+       * by 3 arguments per collected attribute, we are left with a maximum
+       * number of supported attributes of (127 - 5) / 3 = 40.
+       *
+       * In reality, nobody is ever going to call us with anywhere close to
+       * 40 attributes to collect, so it is safe to assume that if i > 40
+       * then the user has given some invalid or repeated arguments.  These
+       * problems will be caught and reported at the end of the function.
+       *
+       * We know at this point that we have an error, but we don't know
+       * what error it is, so just continue...
+       */
+      if (i < 40)
+        collected |= (G_GUINT64_CONSTANT(1) << i);
+
+      value = attribute_values[i];
+
+      if (value == NULL && mandatory)
+        {
+          g_set_error (error, G_MARKUP_ERROR,
+                       G_MARKUP_ERROR_MISSING_ATTRIBUTE,
+                       "element '%s' requires attribute '%s'",
+                       element_name, attr);
+
+          va_end (ap);
+          goto failure;
+        }
+
+      switch (type)
+        {
+        case G_MARKUP_COLLECT_STRING:
+          {
+            const char **str_ptr;
+
+            str_ptr = va_arg (ap, const char **);
+
+            if (str_ptr != NULL)
+              *str_ptr = value;
+          }
+          break;
+
+        case G_MARKUP_COLLECT_STRDUP:
+          {
+            char **str_ptr;
+
+            str_ptr = va_arg (ap, char **);
+
+            if (str_ptr != NULL)
+              *str_ptr = g_strdup (value);
+          }
+          break;
+
+        case G_MARKUP_COLLECT_BOOLEAN:
+        case G_MARKUP_COLLECT_TRISTATE:
+          if (value == NULL)
+            {
+              gboolean *bool_ptr;
+
+              bool_ptr = va_arg (ap, gboolean *);
+
+              if (bool_ptr != NULL)
+                {
+                  if (type == G_MARKUP_COLLECT_TRISTATE)
+                    /* constructivists rejoice!
+                     * neither false nor true...
+                     */
+                    *bool_ptr = -1;
+
+                  else /* G_MARKUP_COLLECT_BOOLEAN */
+                    *bool_ptr = FALSE;
+                }
+            }
+          else
+            {
+              if (!g_markup_parse_boolean (value, va_arg (ap, gboolean *)))
+                {
+                  g_set_error (error, G_MARKUP_ERROR,
+                               G_MARKUP_ERROR_INVALID_CONTENT,
+                               "element '%s', attribute '%s', value '%s' "
+                               "cannot be parsed as a boolean value",
+                               element_name, attr, value);
+
+                  va_end (ap);
+                  goto failure;
+                }
+            }
+
+          break;
+
+        default:
+          g_assert_not_reached ();
+        }
+
+      type = va_arg (ap, GMarkupCollectType);
+      attr = va_arg (ap, const char *);
+      written++;
+    }
+  va_end (ap);
+
+  /* ensure we collected all the arguments */
+  for (i = 0; attribute_names[i]; i++)
+    if ((collected & (G_GUINT64_CONSTANT(1) << i)) == 0)
+      {
+        /* attribute not collected:  could be caused by two things.
+         *
+         * 1) it doesn't exist in our list of attributes
+         * 2) it existed but was matched by a duplicate attribute earlier
+         *
+         * find out.
+         */
+        int j;
+
+        for (j = 0; j < i; j++)
+          if (strcmp (attribute_names[i], attribute_names[j]) == 0)
+            /* duplicate! */
+            break;
+
+        /* j is now the first occurrence of attribute_names[i] */
+        if (i == j)
+          g_set_error (error, G_MARKUP_ERROR,
+                       G_MARKUP_ERROR_UNKNOWN_ATTRIBUTE,
+                       "attribute '%s' invalid for element '%s'",
+                       attribute_names[i], element_name);
+        else
+          g_set_error (error, G_MARKUP_ERROR,
+                       G_MARKUP_ERROR_INVALID_CONTENT,
+                       "attribute '%s' given multiple times for element '%s'",
+                       attribute_names[i], element_name);
+
+        goto failure;
+      }
+
+  return TRUE;
+
+failure:
+  /* replay the above to free allocations */
+  type = first_type;
+  attr = first_attr;
+
+  va_start (ap, first_attr);
+  while (type != G_MARKUP_COLLECT_INVALID)
+    {
+      gpointer ptr;
+
+      ptr = va_arg (ap, gpointer);
+
+      if (ptr == NULL)
+        continue;
+
+      switch (type & (G_MARKUP_COLLECT_OPTIONAL - 1))
+        {
+        case G_MARKUP_COLLECT_STRDUP:
+          if (written)
+            g_free (*(char **) ptr);
+
+        case G_MARKUP_COLLECT_STRING:
+          *(char **) ptr = NULL;
+          break;
+
+        case G_MARKUP_COLLECT_BOOLEAN:
+          *(gboolean *) ptr = FALSE;
+          break;
+
+        case G_MARKUP_COLLECT_TRISTATE:
+          *(gboolean *) ptr = -1;
+          break;
+        }
+
+      type = va_arg (ap, GMarkupCollectType);
+      attr = va_arg (ap, const char *);
+
+      if (written)
+        written--;
+    }
+  va_end (ap);
+
+  return FALSE;
+}