[Bf-blender-cvs] [cfb6ffd48f7] blender-v2.81-release: Fix T70386: Crash when snapping to edges in specific situations

[mano-wii]

Commit: cfb6ffd48f77c338628c9546accbafd5c5b4175c
Author: mano-wii
Date:   Tue Oct 15 14:59:16 2019 -0300
Branches: blender-v2.81-release
https://developer.blender.org/rBcfb6ffd48f77c338628c9546accbafd5c5b4175c

Fix T70386: Crash when snapping to edges in specific situations

The callbacks get elements through indexes,
so make sure they're not "dirty".

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

M	source/blender/editors/transform/transform_snap_object.c

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

diff --git a/source/blender/editors/transform/transform_snap_object.c b/source/blender/editors/transform/transform_snap_object.c
index b31816b2605..f35a2808f22 100644
--- a/source/blender/editors/transform/transform_snap_object.c
+++ b/source/blender/editors/transform/transform_snap_object.c
@@ -2368,6 +2368,7 @@ static short snapEditMesh(SnapObjectContext *sctx,
 
   if (treedata_vert && (snapdata->snap_to_flag & SCE_SNAP_MODE_VERTEX)) {
     BM_mesh_elem_table_ensure(em->bm, BM_VERT);
+    BM_mesh_elem_index_ensure(em->bm, BM_VERT);
     BLI_bvhtree_find_nearest_projected(treedata_vert->tree,
                                        lpmat,
                                        snapdata->win_size,
@@ -2383,6 +2384,7 @@ static short snapEditMesh(SnapObjectContext *sctx,
     int last_index = nearest.index;
     nearest.index = -1;
     BM_mesh_elem_table_ensure(em->bm, BM_EDGE | BM_VERT);
+    BM_mesh_elem_index_ensure(em->bm, BM_EDGE | BM_VERT);
     BLI_bvhtree_find_nearest_projected(treedata_edge->tree,
                                        lpmat,
                                        snapdata->win_size,