[Bf-blender-cvs] [19bddbf] master: Fix T40079: cycles crash with objects that have hair motion blur, but no triangle motion.

[Brecht Van Lommel]

Commit: 19bddbfc54110b55ead9b538d9958842cca6d98e
Author: Brecht Van Lommel
Date:   Thu May 8 15:25:16 2014 +0200
https://developer.blender.org/rB19bddbfc54110b55ead9b538d9958842cca6d98e

Fix T40079: cycles crash with objects that have hair motion blur, but no triangle motion.

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

M	intern/cycles/render/mesh.cpp

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

diff --git a/intern/cycles/render/mesh.cpp b/intern/cycles/render/mesh.cpp
index 9607892..9c5ddd5 100644
--- a/intern/cycles/render/mesh.cpp
+++ b/intern/cycles/render/mesh.cpp
@@ -346,7 +346,7 @@ void Mesh::add_vertex_normals()
 	Attribute *attr_mP = attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
 	Attribute *attr_mN = attributes.find(ATTR_STD_MOTION_VERTEX_NORMAL);
 
-	if(has_motion_blur() && !attr_mN) {
+	if(has_motion_blur() && attr_mP && !attr_mN) {
 		/* create attribute */
 		attr_mN = attributes.add(ATTR_STD_MOTION_VERTEX_NORMAL);