Commit c1c8fdab authored by Ronald S. Bultje's avatar Ronald S. Bultje Committed by Derek Buitenhuis

compat/vsnprintf: return number of bytes required on truncation.

This conforms to C99, but requires Windows >= XP.
Signed-off-by: default avatarDerek Buitenhuis <derek.buitenhuis@gmail.com>
parent 3f7fd59d
...@@ -26,6 +26,10 @@ ...@@ -26,6 +26,10 @@
#include "libavutil/error.h" #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, ...) int avpriv_snprintf(char *s, size_t n, const char *fmt, ...)
{ {
va_list ap; va_list ap;
...@@ -42,9 +46,10 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt, ...@@ -42,9 +46,10 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt,
va_list ap) va_list ap)
{ {
int ret; int ret;
va_list ap_copy;
if (n == 0) if (n == 0)
return 0; return _vscprintf(fmt, ap);
else if (n > INT_MAX) else if (n > INT_MAX)
return AVERROR(EOVERFLOW); return AVERROR(EOVERFLOW);
...@@ -55,9 +60,11 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt, ...@@ -55,9 +60,11 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt,
* _snprintf/_vsnprintf() to workaround this problem. * _snprintf/_vsnprintf() to workaround this problem.
* See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */ * See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */
memset(s, 0, n); 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) if (ret == -1)
ret = n; ret = _vscprintf(fmt, ap);
return ret; return ret;
} }
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