[Bf-blender-cvs] [f6c615a8c28] master: Fix T58819: Weight paint gradient crash

[Campbell Barton]

Commit: f6c615a8c287183b59884a24065273f35cb7a578
Author: Campbell Barton
Date:   Thu Dec 6 11:19:18 2018 +1100
Branches: master
https://developer.blender.org/rBf6c615a8c287183b59884a24065273f35cb7a578

Fix T58819: Weight paint gradient crash

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

M	source/blender/editors/sculpt_paint/paint_vertex_weight_ops.c

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

diff --git a/source/blender/editors/sculpt_paint/paint_vertex_weight_ops.c b/source/blender/editors/sculpt_paint/paint_vertex_weight_ops.c
index 21965bb30d8..28f5c1304c8 100644
--- a/source/blender/editors/sculpt_paint/paint_vertex_weight_ops.c
+++ b/source/blender/editors/sculpt_paint/paint_vertex_weight_ops.c
@@ -687,13 +687,15 @@ static int paint_weight_gradient_modal(bContext *C, wmOperator *op, const wmEven
 
 	if (ret & OPERATOR_CANCELLED) {
 		Object *ob = CTX_data_active_object(C);
-		Mesh *me = ob->data;
-		if (vert_cache->wpp.wpaint_prev) {
-			BKE_defvert_array_free_elems(me->dvert, me->totvert);
-			BKE_defvert_array_copy(me->dvert, vert_cache->wpp.wpaint_prev, me->totvert);
-			wpaint_prev_destroy(&vert_cache->wpp);
+		if (vert_cache != NULL) {
+			Mesh *me = ob->data;
+			if (vert_cache->wpp.wpaint_prev) {
+				BKE_defvert_array_free_elems(me->dvert, me->totvert);
+				BKE_defvert_array_copy(me->dvert, vert_cache->wpp.wpaint_prev, me->totvert);
+				wpaint_prev_destroy(&vert_cache->wpp);
+			}
+			MEM_freeN(vert_cache);
 		}
-		MEM_freeN(vert_cache);
 
 		DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
 		WM_event_add_notifier(C, NC_OBJECT | ND_DRAW, ob);