From 4134bdc75c8f7fe354d850e84503546d743e9382 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Mon, 17 Feb 2014 15:15:49 +1100
Subject: [PATCH] Fix for rare crash in recent mask option to check overlaps

---
 source/blender/blenlib/intern/scanfill_utils.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/source/blender/blenlib/intern/scanfill_utils.c b/source/blender/blenlib/intern/scanfill_utils.c
index a6477d45054..afa40c0b3fe 100644
--- a/source/blender/blenlib/intern/scanfill_utils.c
+++ b/source/blender/blenlib/intern/scanfill_utils.c
@@ -258,6 +258,12 @@ static bool scanfill_preprocess_self_isect(
 
 				LinkData *isect_link;
 
+				if (UNLIKELY(e_ls == NULL)) {
+					/* only happens in very rare cases (entirely overlapping splines).
+					 * in this case se can't do much useful. but at least don't crash */
+					continue;
+				}
+
 				/* maintain coorect terminating edge */
 				if (pi->edge_last == eed) {
 					pi->edge_last = NULL;