[Bf-blender-cvs] [140d3833937] blender2.8: Fix T57935: Crash Alt clicking w/ poly build tool

[Campbell Barton]

Commit: 140d383393764f28405b34775b2e0dc22c51e5a6
Author: Campbell Barton
Date:   Wed Nov 21 05:21:18 2018 +1100
Branches: blender2.8
https://developer.blender.org/rB140d383393764f28405b34775b2e0dc22c51e5a6

Fix T57935: Crash Alt clicking w/ poly build tool

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

M	source/blender/editors/mesh/editmesh_polybuild.c

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

diff --git a/source/blender/editors/mesh/editmesh_polybuild.c b/source/blender/editors/mesh/editmesh_polybuild.c
index 882ee3092b4..c175102511a 100644
--- a/source/blender/editors/mesh/editmesh_polybuild.c
+++ b/source/blender/editors/mesh/editmesh_polybuild.c
@@ -426,7 +426,10 @@ static int edbm_polybuild_dissolve_at_cursor_invoke(
 	BMEditMesh *em = vc.em;
 	BMesh *bm = em->bm;
 
-	if (ele_act->head.htype == BM_EDGE) {
+	if (ele_act == NULL) {
+		/* pass */
+	}
+	else if (ele_act->head.htype == BM_EDGE) {
 		BMEdge *e_act = (BMEdge *)ele_act;
 		BMLoop *l_a, *l_b;
 		if (BM_edge_loop_pair(e_act, &l_a, &l_b)) {