1 files changed, 49 insertions, 0 deletions
diff --git a/lib/unistr/u-strstr.h b/lib/unistr/u-strstr.h
new file mode 100644
index 00000000..55b5a31d
--- /dev/null
+++ b/lib/unistr/u-strstr.h
@@ -0,0 +1,49 @@
+/* Substring test for UTF-8/UTF-16/UTF-32 strings.
+   Copyright (C) 1999, 2002, 2006 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2002.
+
+   This program 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 3 of the License, 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+UNIT *
+FUNC (const UNIT *haystack, const UNIT *needle)
+{
+  UNIT first = needle[0];
+
+  /* Is needle empty?  */
+  if (first == 0)
+    return (UNIT *) haystack;
+
+  /* Is needle nearly empty?  */
+  if (needle[1] == 0)
+    return U_STRCHR (haystack, first);
+
+  /* Search for needle's first unit.  */
+  for (; *haystack != 0; haystack++)
+    if (*haystack == first)
+      {
+	/* Compare with needle's remaining units.  */
+	const UNIT *hptr = haystack + 1;
+	const UNIT *nptr = needle + 1;
+	for (;;)
+	  {
+	    if (*hptr != *nptr)
+	      break;
+	    hptr++; nptr++;
+	    if (*nptr == 0)
+	      return (UNIT *) haystack;
+	  }
+      }
+
+  return NULL;
+}