Fix T82388: Sculpt mode: Unexpected undo behavior.

Issue exposed by rB4c7b1766a7f1.

Main idea is that non-memfile first undo step should check into previous
memfile and tag the ID it is editing as `future_changed`.

That way, when we go back and undo to the memfile, said IDs are properly
detected as changed and re-read from the memfile.

Otherwise, undo system sees them as unchanged, and just re-use the
current data instead.

Note that currently only Sculpt mode seems affected (probably because it
is storing the mode switch itself as a Sculpt undo step instead of a
memfile one), but similar action might be needed in some other cases
too.

Maniphest Tasks: T82388

Differential Revision: https://developer.blender.org/D9510

1 files changed, 1 insertions, 1 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt_cloth.c b/source/blender/editors/sculpt_paint/sculpt_cloth.c
index 20b164fa80c..f8165890cc4 100644
--- a/source/blender/editors/sculpt_paint/sculpt_cloth.c
+++ b/source/blender/editors/sculpt_paint/sculpt_cloth.c
@@ -1548,7 +1548,7 @@ static int sculpt_cloth_filter_invoke(bContext *C, wmOperator *op, const wmEvent
   /* Needs mask data to be available as it is used when solving the constraints. */
   BKE_sculpt_update_object_for_edit(depsgraph, ob, true, true, false);
 
-  SCULPT_undo_push_begin("Cloth filter");
+  SCULPT_undo_push_begin(ob, "Cloth filter");
   SCULPT_filter_cache_init(C, ob, sd, SCULPT_UNDO_COORDS);
 
   ss->filter_cache->automasking = SCULPT_automasking_cache_init(sd, NULL, ob);