Theme override checkbox is oblivious to undo

[KoBeWi]

Godot version

3.4 / 4.0 03cfdf8

System information

W10

Issue description

The checkbox next to theme override properties takes effect when toggled, but the toggle isn't stored in the undo history in any way. When you add e.g. a color override, you can undo it, but the checkbox will still be pressed (until you re-select node). When you uncheck the checkbox to clear override, you won't be able to undo it.

Steps to reproduce

1. Add e.g. Label
2. Add override to font_color theme property
3. Undo it
4. Redo
5. Uncheck the checkbox
6. Undo / redo
7. Weird things will happen

Minimal reproduction project

No response

[KoBeWi]

@Calinou This also applies to master; I edited the version to be more clear.

[KoBeWi]

Seems better than before, but it's still not fixed yet:

You can't undo to pre-checkbox state.