1 files changed, 88 insertions, 0 deletions
diff --git a/libs/libcurl/src/strequal.c b/libs/libcurl/src/strequal.c
new file mode 100644
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+++ b/libs/libcurl/src/strequal.c
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+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * SPDX-License-Identifier: curl
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#include <curl/curl.h>
+#include "strcase.h"
+
+/*
+ * curl_strequal() is for doing "raw" case insensitive strings. This is meant
+ * to be locale independent and only compare strings we know are safe for
+ * this. See https://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for
+ * further explanations as to why this function is necessary.
+ */
+
+static int casecompare(const char *first, const char *second)
+{
+  while(*first) {
+    if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second))
+      /* get out of the loop as soon as they do not match */
+      return 0;
+    first++;
+    second++;
+  }
+  /* If we are here either the strings are the same or the length is different.
+     We can just test if the "current" character is non-zero for one and zero
+     for the other. Note that the characters may not be exactly the same even
+     if they match, we only want to compare zero-ness. */
+  return !*first == !*second;
+}
+
+static int ncasecompare(const char *first, const char *second, size_t max)
+{
+  while(*first && max) {
+    if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second))
+      return 0;
+    max--;
+    first++;
+    second++;
+  }
+  if(0 == max)
+    return 1; /* they are equal this far */
+
+  return Curl_raw_toupper(*first) == Curl_raw_toupper(*second);
+}
+
+/* --- public function --- */
+int curl_strequal(const char *first, const char *second)
+{
+  if(first && second)
+    /* both pointers point to something then compare them */
+    return casecompare(first, second);
+
+  /* if both pointers are NULL then treat them as equal */
+  return NULL == first && NULL == second;
+}
+
+/* --- public function --- */
+int curl_strnequal(const char *first, const char *second, size_t max)
+{
+  if(first && second)
+    /* both pointers point to something then compare them */
+    return ncasecompare(first, second, max);
+
+  /* if both pointers are NULL then treat them as equal if max is non-zero */
+  return NULL == first && NULL == second && max;
+}