Bug 798873 Patch 3 - flex_string fix for Windows vsnprintf r=jesup a=…

…bajaj
johnshih · Oct 18, 2012 · 45eec6f · 45eec6f
1 parent d80a54a
commit 45eec6f
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/media/webrtc/signaling/src/sipcc/cpr/common/cpr_string.c b/media/webrtc/signaling/src/sipcc/cpr/common/cpr_string.c
@@ -213,6 +213,14 @@ void flex_string_sprintf(flex_string *fs, const char *format, ...) {
   vsnprintf_result = vsnprintf(fs->buffer + fs->string_length, fs->buffer_length - fs->string_length, format, ap);
   va_end(ap);
 
+  /* Special case just for Windows where vsnprintf is broken
+     and returns -1 if buffer too large unless you size it 0. */
+  if (vsnprintf_result < 0) {
+    va_start(ap, format);
+    vsnprintf_result = vsnprintf(NULL, 0, format, ap);
+    va_end(ap);
+  }
+
   if (fs->string_length + vsnprintf_result >= fs->buffer_length) {
     /* Buffer overflow, resize */
     flex_string_check_alloc(fs, fs->string_length + vsnprintf_result + 1);