From 663c21d4ac1a011f71fe48a6a8b6934cd2ef1a4b Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Fri, 14 Sep 2012 16:03:25 -0400 Subject: [PATCH] compat/vsnprintf: return number of bytes required on truncation. This conforms to C99, but requires Windows >= XP. --- compat/msvcrt/snprintf.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/compat/msvcrt/snprintf.c b/compat/msvcrt/snprintf.c index 36f6dd17cb..6787aad1c6 100644 --- a/compat/msvcrt/snprintf.c +++ b/compat/msvcrt/snprintf.c @@ -43,9 +43,10 @@ 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); @@ -56,9 +57,11 @@ 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; }