+2024-06-30 Paul Eggert <eggert@cs.ucla.edu>
+
+ strnlen: avoid undefined memcmp behavior
+ Problem reported by Po Lu in:
+ https://lists.gnu.org/r/bug-gnulib/2024-06/msg00288.html
+ * config/srclist.txt: Don’t mention strnlen.c even in a comment,
+ as the Gnulib and glibc implementations have diverged for
+ portability reasons, and they’re never likely to merge.
+ * lib/strnlen.c (strnlen): Avoid undefined behavior if
+ the array S points to has fewer than MAXLEN bytes.
+
2024-06-28 Bruno Haible <bruno@clisp.org>
time: Fix test failure on FreeBSD.
#$LIBCSRC string/strcasecmp.c lib gpl
#$LIBCSRC string/strchrnul.c lib gpl
#$LIBCSRC string/strerror.c lib gpl
-#$LIBCSRC string/strnlen.c lib gpl
#$LIBCSRC sysdeps/posix/gettimeofday.c lib gpl
#$LIBCSRC sysdeps/posix/rename.c lib gpl
#$LIBCSRC sysdeps/unix/mkdir.c lib gpl
/* Find the length of STRING, but scan at most MAXLEN characters.
- Copyright (C) 2005-2007, 2009-2023 Free Software Foundation, Inc.
- Written by Simon Josefsson.
+ Copyright (C) 2005-2007, 2009-2024 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
#include <string.h>
-/* Find the length of STRING, but scan at most MAXLEN characters.
- If no '\0' terminator is found in that many characters, return MAXLEN. */
+/* Find the length of S, but scan at most MAXLEN bytes.
+ S must be a string if it starts with fewer than MAXLEN initialized bytes.
+ If no '\0' terminator is found in that many bytes, return MAXLEN. */
size_t
-strnlen (const char *string, size_t maxlen)
+strnlen (const char *s, size_t maxlen)
{
- const char *end = memchr (string, '\0', maxlen);
- return end ? (size_t) (end - string) : maxlen;
+ /* Do not use memchr, because on some platforms memchr has
+ undefined behavior if MAXLEN exceeds the number of bytes in S. */
+ size_t i;
+ for (i = 0; i < maxlen && s[i]; i++)
+ continue;
+ return i;
}