[Bf-blender-cvs] [9de3ed5c823] master: Fix T97490: snap to multiple objects with linked data can crash

[Germano Cavalcante]

Commit: 9de3ed5c823ed79c3584765141d4f1c160add4d3
Author: Germano Cavalcante
Date:   Thu Apr 21 14:07:57 2022 -0300
Branches: master
https://developer.blender.org/rB9de3ed5c823ed79c3584765141d4f1c160add4d3

Fix T97490: snap to multiple objects with linked data can crash

The problem is old.

rB52be06301257 (fixed by rB4b35d6950d4f) just masked it.

`Object->data`, on evaluated objects, is not a safe pointer to get
objects with the same `BMEditData`.

Use `Object->runtime.data_orig` instead.

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

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

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

diff --git a/source/blender/editors/transform/transform_snap_object.cc b/source/blender/editors/transform/transform_snap_object.cc
index ab78ef6a5aa..abeb376a9a6 100644
--- a/source/blender/editors/transform/transform_snap_object.cc
+++ b/source/blender/editors/transform/transform_snap_object.cc
@@ -242,7 +242,7 @@ static SnapObjectData *snap_object_data_lookup(SnapObjectContext *sctx, Object *
   if (sod == nullptr) {
     if (sctx->cache.data_to_object_map != nullptr) {
       ob_eval = static_cast<Object *>(
-          BLI_ghash_lookup(sctx->cache.data_to_object_map, ob_eval->data));
+          BLI_ghash_lookup(sctx->cache.data_to_object_map, ob_eval->runtime.data_orig));
       /* Could be NULl when mixing edit-mode and non edit-mode objects. */
       if (ob_eval != nullptr) {
         sod = static_cast<SnapObjectData *>(BLI_ghash_lookup(sctx->cache.object_map, ob_eval));
@@ -369,7 +369,7 @@ static SnapObjectData *snap_object_data_editmesh_get(SnapObjectContext *sctx,
       sctx->cache.data_to_object_map = BLI_ghash_ptr_new(__func__);
     }
     void **ob_p;
-    if (BLI_ghash_ensure_p(sctx->cache.data_to_object_map, ob_eval->data, &ob_p)) {
+    if (BLI_ghash_ensure_p(sctx->cache.data_to_object_map, ob_eval->runtime.data_orig, &ob_p)) {
       ob_eval = static_cast<Object *>(*ob_p);
     }
     else {