[Bf-blender-cvs] [369e1d46f0d] master: Fix T56545: Material referencing missing UV crash

[Campbell Barton]

Commit: 369e1d46f0dbdd7904de7a5350ae7825800588df
Author: Campbell Barton
Date:   Wed Jan 9 01:04:28 2019 +1100
Branches: master
https://developer.blender.org/rB369e1d46f0dbdd7904de7a5350ae7825800588df

Fix T56545: Material referencing missing UV crash

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

M	source/blender/draw/intern/draw_cache_impl_mesh.c

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

diff --git a/source/blender/draw/intern/draw_cache_impl_mesh.c b/source/blender/draw/intern/draw_cache_impl_mesh.c
index 9d9f7c47b14..fd9c44431b7 100644
--- a/source/blender/draw/intern/draw_cache_impl_mesh.c
+++ b/source/blender/draw/intern/draw_cache_impl_mesh.c
@@ -434,6 +434,11 @@ static void mesh_cd_calc_used_gpu_layers(
 							layer = (name[0] != '\0') ?
 							        CustomData_get_named_layer(cd_ldata, CD_MLOOPUV, name) :
 							        CustomData_get_active_layer(cd_ldata, CD_MLOOPUV);
+
+							/* Only fallback to orco (below) when we have no UV layers, see: T56545 */
+							if (layer == -1 && name[0] != '\0') {
+								layer = CustomData_get_active_layer(cd_ldata, CD_MLOOPUV);
+							}
 						}
 						if (layer != -1) {
 							cd_lused[CD_TANGENT] |= (1 << layer);