[Bf-blender-cvs] [6f5d1e2] master: Add missing spin-lock to IMB_makeSingleUser

[Campbell Barton]

Commit: 6f5d1e257e727d73d62a1ab4efbbd9fa1332a4e6
Author: Campbell Barton
Date:   Wed Sep 2 23:23:44 2015 +1000
Branches: master
https://developer.blender.org/rB6f5d1e257e727d73d62a1ab4efbbd9fa1332a4e6

Add missing spin-lock to IMB_makeSingleUser

===================================================================

M	source/blender/imbuf/intern/allocimbuf.c

===================================================================

diff --git a/source/blender/imbuf/intern/allocimbuf.c b/source/blender/imbuf/intern/allocimbuf.c
index 9042c4b..b8771e3 100644
--- a/source/blender/imbuf/intern/allocimbuf.c
+++ b/source/blender/imbuf/intern/allocimbuf.c
@@ -206,7 +206,18 @@ ImBuf *IMB_makeSingleUser(ImBuf *ibuf)
 {
 	ImBuf *rval;
 
-	if (!ibuf || ibuf->refcounter == 0) { return ibuf; }
+	if (ibuf) {
+		bool is_single;
+		BLI_spin_lock(&refcounter_spin);
+		is_single = (ibuf->refcounter == 0);
+		BLI_spin_unlock(&refcounter_spin);
+		if (is_single) {
+			return ibuf;
+		}
+	}
+	else {
+		return NULL;
+	}
 
 	rval = IMB_dupImBuf(ibuf);