[Bf-blender-cvs] [bc63d6f39ad] master: Fix T55095: Undo crash w/ linked library data

[Campbell Barton]

Commit: bc63d6f39ade353610669e97bdbcbbb184ef48c8
Author: Campbell Barton
Date:   Wed Aug 8 19:16:43 2018 +1000
Branches: master
https://developer.blender.org/rBbc63d6f39ade353610669e97bdbcbbb184ef48c8

Fix T55095: Undo crash w/ linked library data

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

M	source/blender/blenkernel/intern/undo_system.c

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

diff --git a/source/blender/blenkernel/intern/undo_system.c b/source/blender/blenkernel/intern/undo_system.c
index 2231f43c9c3..0ebfb4065e4 100644
--- a/source/blender/blenkernel/intern/undo_system.c
+++ b/source/blender/blenkernel/intern/undo_system.c
@@ -864,7 +864,7 @@ ID *BKE_undosys_ID_map_lookup_with_prev(const UndoIDPtrMap *map, ID *id_src, ID
 		return id_prev_match[1];
 	}
 	else {
-		ID *id_dst = BKE_undosys_ID_map_lookup(map, id_src);
+		ID *id_dst = (id_src->lib == NULL) ? BKE_undosys_ID_map_lookup(map, id_src) : id_src;
 		id_prev_match[0] = id_src;
 		id_prev_match[1] = id_dst;
 		return id_dst;