From f13bede758cd419c407a9124a13b7955f8ea0068 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 28 Jan 2009 20:31:19 +0000
Subject: [PATCH] Fix an unlikely degenerate case of evutil_vsnprintf

svn:r1067
---
 evutil.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/evutil.c b/evutil.c
index 2dea5837..53cb75d3 100644
--- a/evutil.c
+++ b/evutil.c
@@ -340,18 +340,18 @@ evutil_snprintf(char *buf, size_t buflen, const char *format, ...)
 int
 evutil_vsnprintf(char *buf, size_t buflen, const char *format, va_list ap)
 {
+        int r;
+        if (!buflen)
+                return 0;
 #ifdef _MSC_VER
-	int r = _vsnprintf(buf, buflen, format, ap);
-	buf[buflen-1] = '\0';
-	if (r >= 0)
-		return r;
-	else
-		return _vscprintf(format, ap);
+	r = _vsnprintf(buf, buflen, format, ap);
+	if (r < 0)
+		r = _vscprintf(format, ap);
 #else
-	int r = vsnprintf(buf, buflen, format, ap);
+	r = vsnprintf(buf, buflen, format, ap);
+#endif
 	buf[buflen-1] = '\0';
 	return r;
-#endif
 }
 
 #define USE_INTERNAL_NTOP