[Bf-blender-cvs] [41a4967] master: Fix T49003: Cycles volumes have wrong results after recent microdisp commits

[Mai Lavelle]

Commit: 41a4967b301f2faaee5ab519f5373c3b6cab33c0
Author: Mai Lavelle
Date:   Tue Aug 2 15:27:41 2016 -0400
Branches: master
https://developer.blender.org/rB41a4967b301f2faaee5ab519f5373c3b6cab33c0

Fix T49003: Cycles volumes have wrong results after recent microdisp commits

Problem was that sd->prim can be -1 for volumes and was causing check in subd
code to access out of bounds

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

M	intern/cycles/kernel/geom/geom_subd_triangle.h

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

diff --git a/intern/cycles/kernel/geom/geom_subd_triangle.h b/intern/cycles/kernel/geom/geom_subd_triangle.h
index e4597ab..bf9be18 100644
--- a/intern/cycles/kernel/geom/geom_subd_triangle.h
+++ b/intern/cycles/kernel/geom/geom_subd_triangle.h
@@ -22,7 +22,7 @@ CCL_NAMESPACE_BEGIN
 
 ccl_device_inline uint subd_triangle_patch(KernelGlobals *kg, const ShaderData *sd)
 {
-	return kernel_tex_fetch(__tri_patch, ccl_fetch(sd, prim));
+	return (ccl_fetch(sd, prim) != PRIM_NONE) ? kernel_tex_fetch(__tri_patch, ccl_fetch(sd, prim)) : ~0;
 }
 
 /* UV coords of triangle within patch */