4162aeee5f
The new brushes don't update `SculptSession::orig_cos` (which is good, it's not necessary since it's just a copy of the active shape key data or the original mesh's vertex positions). To fix the problem with the undo system, access those two arrays directly instead. Once all the uses of the "proxy" system are removed, `orig_cos` can be removed too. Pull Request: https://projects.blender.org/blender/blender/pulls/123922