Undo savestate/loadstate

[andres-asm]

• Undo Load state reverts the game state to the exact point before loading was triggered (creates a gamename.undo file)
• Undo Load state loads the backup save state generated right before saving such a state

Only tested on windows

[rz5]

Some observations:

1. If no savestates exist in the savestate dir, both new Undo options will print about the same message in the OSD:
   " Failed to load state from "path/to/savestate/dir" "
   Ideally, 'Undo Load State' would print out e.g. "Nothing to undo".

2. If we do the following operations: Save State > Save State > Undo Save State > Undo Load State
   The last operation will fail and the expectation is that, since 'Undo Save State' LOADS the file 'content_name.last', the last operation undoes THAT.

3. Undo Load State relies on a file generically called content_name.undo. The specification of this operation is that it shouldn't rely on anything on disk, it's an option that makes sense per session but not across sessions.
   At least that's how Dolphin seems to do it.

[andres-asm]

1. ok
2. I don't really understand
3. I don't really care about what dolphin does, I don't feel like splitting the content save operation in two to make save states in memory

[Jakobud]

Is this something documented somewhere? How do you use this feature?