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_intern.h b/source/blender/editors/sculpt_paint/sculpt_intern.h
index 1a596909d8d..c5db078617f 100644
--- a/source/blender/editors/sculpt_paint/sculpt_intern.h
+++ b/source/blender/editors/sculpt_paint/sculpt_intern.h
@@ -1085,7 +1085,7 @@ void SCULPT_cache_free(StrokeCache *cache);
 SculptUndoNode *SCULPT_undo_push_node(Object *ob, PBVHNode *node, SculptUndoType type);
 SculptUndoNode *SCULPT_undo_get_node(PBVHNode *node);
 SculptUndoNode *SCULPT_undo_get_first_node(void);
-void SCULPT_undo_push_begin(const char *name);
+void SCULPT_undo_push_begin(struct Object *ob, const char *name);
 void SCULPT_undo_push_end(void);
 void SCULPT_undo_push_end_ex(const bool use_nested_undo);