Bastien Montagne
bc090387ac
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