diff options
Diffstat (limited to 'textscreen/txt_sdl.c')
-rw-r--r-- | textscreen/txt_sdl.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/textscreen/txt_sdl.c b/textscreen/txt_sdl.c index 860adfa6..984a2e75 100644 --- a/textscreen/txt_sdl.c +++ b/textscreen/txt_sdl.c @@ -906,6 +906,8 @@ void TXT_StringConcat(char *dest, const char *src, size_t dest_len) // Safe, portable vsnprintf(). int TXT_vsnprintf(char *buf, size_t buf_len, const char *s, va_list args) { + int result; + if (buf_len < 1) { return 0; @@ -914,8 +916,17 @@ int TXT_vsnprintf(char *buf, size_t buf_len, const char *s, va_list args) // Windows (and other OSes?) has a vsnprintf() that doesn't always // append a trailing \0. So we must do it, and write into a buffer // that is one byte shorter; otherwise this function is unsafe. - buf[buf_len - 1] = '\0'; - return vsnprintf(buf, buf_len - 1, s, args); + result = vsnprintf(buf, buf_len, s, args); + + // If truncated, change the final char in the buffer to a \0. + // A negative result indicates a truncated buffer on Windows. + if (result < 0 || result >= buf_len) + { + buf[buf_len - 1] = '\0'; + result = buf_len - 1; + } + + return result; } // Safe, portable snprintf(). |