From 610a7d6954ea63f7f01772533338efd7b6a14cfe Mon Sep 17 00:00:00 2001
From: duncanspumpkin <duncans_pumpkin@hotmail.co.uk>
Date: Tue, 20 Oct 2015 20:40:17 +0100
Subject: [PATCH] Fix #2095. Bitscanforward needs to return -1 if nothing
 found.

---
 src/util/util.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/util/util.c b/src/util/util.c
index d7f081357b..e980f4c2b8 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -144,8 +144,8 @@ int bitscanforward(int source)
 	int i;
 
 	#if _MSC_VER >= 1400 // Visual Studio 2005
-		_BitScanForward(&i, source);
-		return i;
+		uint8 success = _BitScanForward(&i, source);
+		return success != 0 ? i : -1;
 	#else
 	for (i = 0; i < 32; i++)
 		if (source & (1 << i))