> 2011-09-22 Bruno Haible <br...@clisp.org>
>
> strerror_r-posix: Avoid a link error on MSVC.
> * m4/strerror_r.m4 (gl_PREREQ_STRERROR_R): Check for snprintf.
> * lib/strerror_r.c (snprintf): Define to _snprintf if it doesn't exist.
Oops, that fixed the link error, but at the cost of a test suite failure:
test-strerror_r.c:119: assertion failed
FAIL: test-strerror_r.exe
The Microsoft _snprintf() function not only has a different return value
convention than ISO C snprintf(), it also does not NUL-terminate the result!
Workaround:
2011-09-25 Bruno Haible <br...@clisp.org>
strerror_r-posix: Fix for MSVC 9.
* lib/strerror_r.c (local_snprintf): New function.
(snprintf): Define to local_snprintf, not to _snprintf.
--- lib/strerror_r.c.orig Sun Sep 25 14:50:08 2011
+++ lib/strerror_r.c Sun Sep 25 14:49:15 2011
@@ -87,9 +87,24 @@
#endif
/* On MSVC, there is no snprintf() function, just a _snprintf().
- It is of lower quality, but sufficient for the simple use here. */
+ It is of lower quality, but sufficient for the simple use here.
+ We only have to make sure to NUL terminate the result (_snprintf
+ does not NUL terminate, like strncpy). */
#if !HAVE_SNPRINTF
-# define snprintf _snprintf
+static int
+local_snprintf (char *buf, size_t buflen, const char *format, ...)
+{
+ va_list args;
+ int result;
+
+ va_start (args, format);
+ result = _vsnprintf (buf, buflen, format, args);
+ va_end (args);
+ if (buflen > 0 && (result < 0 || result >= buflen))
+ buf[buflen - 1] = '\0';
+ return result;
+}
+# define snprintf local_snprintf
#endif
/* Copy as much of MSG into BUF as possible, without corrupting errno.
--
In memoriam Safia Ahmed-jan <http://en.wikipedia.org/wiki/Safia_Ahmed-jan>
