This is a suggestion to enable undoing even after a project has been closed and re-opened later.
Why? Because s*** happens and also it is more in the spirit of ‘non-destructive’ editing.
Real world case that happened: my son lost all the work he was doing on a project because (I think) he accidentally opened a video file with “open file” and probably did an overwrite of the whole edited track, then must have saved. This is a bit of an extreme case of course, but these kinds of errors do happen.
In a more normal workflow you might do some edit / cut or modification close Shotcut and then when reopening may want to go back.
For instance Ardour has this feature and saves the undo history, so when you re-open a session you can still undo stuff which was done previously.
o/ +1 for saving the undo history in the project file (it wouldn’t take a lot of bytes, would it?).
Two more reasons for it:
Other than when a project is peacefully saved, closed and reopened, there are the crashes, for which it’d be nice–imperative, actually!–to have the undo history in the autosaved project file (if restoring an autosaved file is to be akin to continuing the previous, crashed, session).
While even a pretty lengthy undo history wouldn’t take much space in the project file, I get it that it may take up memory. Having it saved in the project file is one–pretty old fashioned–way of conserving RAM (isn’t it?).