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| author | Ronald S. Bultje <rsbultje@gmail.com> | 2012-09-14 18:56:46 +0000 |
|---|---|---|
| committer | Derek Buitenhuis <derek.buitenhuis@gmail.com> | 2012-09-15 14:33:11 -0400 |
| commit | c1c8fdab46414e3518400d6ee18916d2444a06d7 (patch) | |
| tree | 631b4bc2bf7c96ce2bd90491ff2806edf862a45f | |
| parent | 3f7fd59d151a2773f0e2e93e56b6b13ec6e5334b (diff) | |
| download | ffmpeg-c1c8fdab46414e3518400d6ee18916d2444a06d7.tar.gz | |
compat/vsnprintf: return number of bytes required on truncation.
This conforms to C99, but requires Windows >= XP.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
| -rw-r--r-- | compat/msvcrt/snprintf.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/compat/msvcrt/snprintf.c b/compat/msvcrt/snprintf.c index 2cdec74b39..0af7b54353 100644 --- a/compat/msvcrt/snprintf.c +++ b/compat/msvcrt/snprintf.c @@ -26,6 +26,10 @@ #include "libavutil/error.h" +#if !defined(va_copy) && defined(_MSC_VER) +#define va_copy(dst, src) ((dst) = (src)) +#endif + int avpriv_snprintf(char *s, size_t n, const char *fmt, ...) { va_list ap; @@ -42,9 +46,10 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt, va_list ap) { int ret; + va_list ap_copy; if (n == 0) - return 0; + return _vscprintf(fmt, ap); else if (n > INT_MAX) return AVERROR(EOVERFLOW); @@ -55,9 +60,11 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt, * _snprintf/_vsnprintf() to workaround this problem. * See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */ memset(s, 0, n); - ret = _vsnprintf(s, n - 1, fmt, ap); + va_copy(ap_copy, ap); + ret = _vsnprintf(s, n - 1, fmt, ap_copy); + va_end(ap_copy); if (ret == -1) - ret = n; + ret = _vscprintf(fmt, ap); return ret; } |