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-rw-r--r--lib/unistr/u-strstr.h49
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diff --git a/lib/unistr/u-strstr.h b/lib/unistr/u-strstr.h
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+/* 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;
+}