.

1 files changed, 108 insertions, 0 deletions

diff --git a/lib/memcoll.c b/lib/memcoll.c
new file mode 100644
index 000000000..11a61ad60
--- /dev/null
+++ b/lib/memcoll.c
@@ -0,0 +1,108 @@
+/* Locale-specific memory comparison.
+   Copyright 1999 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Contributed by Paul Eggert <eggert@twinsun.com>.  */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifndef __GNUC__
+# ifdef HAVE_ALLOCA_H
+#  include <alloca.h>
+# else
+#  ifdef _AIX
+ #  pragma alloca
+#  else
+#   ifdef _WIN32
+#    include <malloc.h>
+#    include <io.h>
+#   else
+#    ifndef alloca
+char *alloca ();
+#    endif
+#   endif
+#  endif
+# endif
+#endif
+
+#if HAVE_STRING_H
+# include <string.h>
+#endif
+
+/* Compare S1 (with length S1LEN) and S2 (with length S2LEN) according
+   to the LC_COLLATE locale.  S1 and S2 do not overlap, but may be
+   adjacent.  Temporarily modify the bytes after S1 and S2, but
+   restore their original contents before returning.  */
+int
+memcoll (char *s1, size_t s1len, char *s2, size_t s2len)
+{
+  int diff;
+  char n1;
+  char n2;
+
+  /* We will temporarily set the bytes after S1 and S2 to zero, so if
+     S1 and S2 are adjacent, compare to a temporary copy of the
+     earlier, to avoid temporarily stomping on the later.  */
+
+  if (s1 + s1len == s2)
+    {
+      char *s2copy = alloca (s2len + 1);
+      memcpy (s2copy, s2, s2len);
+      s2 = s2copy;
+    }
+
+  if (s2 + s2len == s1)
+    {
+      char *s1copy = alloca (s1len + 1);
+      memcpy (s1copy, s1, s1len);
+      s1 = s1copy;
+    }
+
+  n1 = s1[s1len];  s1[s1len++] = '\0';
+  n2 = s2[s2len];  s2[s2len++] = '\0';
+
+  while (! (diff = strcoll (s1, s2)))
+    {
+      /* strcoll found no difference, but perhaps it was fooled by NUL
+	 characters in the data.  Work around this problem by advancing
+	 past the NUL chars.  */
+      size_t size1 = strlen (s1) + 1;
+      size_t size2 = strlen (s2) + 1;
+      s1 += size1;
+      s2 += size2;
+      s1len -= size1;
+      s2len -= size2;
+
+      if (s1len == 0)
+	{
+	  if (s2len != 0)
+	    diff = -1;
+	  break;
+	}
+      else if (s2len == 0)
+	{
+	  diff = 1;
+	  break;
+	}
+    }
+
+  s1[s1len - 1] = n1;
+  s2[s2len - 1] = n2;
+
+  return diff;
+}