Fix T54098: Crash existing /w dyntopo sculpt

Optionally don't remap indices for objects.

Checking all objects parent's would reference a freed pointer
while freeing all objects.

In the case of dynamic topology there is no use in keeping track
of hook/vertex-parent indices.

Also disable this when creating meshes for undo storage
since adding an undo step shouldn't be modifying other objects.

1 files changed, 5 insertions, 1 deletions

diff --git a/source/blender/editors/mesh/editmesh_tools.c b/source/blender/editors/mesh/editmesh_tools.c
index 4b4f1b2afea..c979a73e964 100644
--- a/source/blender/editors/mesh/editmesh_tools.c
+++ b/source/blender/editors/mesh/editmesh_tools.c
@@ -3357,7 +3357,11 @@ static int edbm_separate_exec(bContext *C, wmOperator *op)
 					}
 
 					if (retval_iter) {
-						BM_mesh_bm_to_me(bm_old, me, (&(struct BMeshToMeshParams){0}));
+						BM_mesh_bm_to_me(
+						        bm_old, me,
+						        (&(struct BMeshToMeshParams){
+						            .calc_object_remap = true,
+						        }));
 
 						DAG_id_tag_update(&me->id, OB_RECALC_DATA);
 						WM_event_add_notifier(C, NC_GEOM | ND_DATA, me);