[Bf-blender-cvs] [2e92791074d] master: Fix crash validating mesh polygons with invalid loop-start

[Campbell Barton]

Commit: 2e92791074deb9cc5f0e96d7621b71cfd79cac1c
Author: Campbell Barton
Date:   Thu Jul 25 13:23:05 2019 +1000
Branches: master
https://developer.blender.org/rB2e92791074deb9cc5f0e96d7621b71cfd79cac1c

Fix crash validating mesh polygons with invalid loop-start

Add check for negative loop-start,
fixes crash validating test file from T67605.

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

M	source/blender/blenkernel/intern/mesh_validate.c

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

diff --git a/source/blender/blenkernel/intern/mesh_validate.c b/source/blender/blenkernel/intern/mesh_validate.c
index dac12233539..c8e75532075 100644
--- a/source/blender/blenkernel/intern/mesh_validate.c
+++ b/source/blender/blenkernel/intern/mesh_validate.c
@@ -1200,7 +1200,7 @@ void BKE_mesh_strip_loose_polysloops(Mesh *me)
     int i = p->loopstart;
     int stop = i + p->totloop;
 
-    if (stop > me->totloop || stop < i) {
+    if (stop > me->totloop || stop < i || p->loopstart < 0) {
       invalid = true;
     }
     else {