Undo broken when both Ripple buttons are active

Ubuntu 20.04
Shotcut 20.11.28

The Undo feature (ex: via Ctrl + Z) is broken when both Ripple buttons are active while performing the action to undo (ex: cutting a clip).

Instructions to duplicate bug:

  1. I begin with this Timeline:
  2. Activate “Ripple trim and drop” and “Ripple edits across all tracks” (circled buttons in image above).
  3. Trim a clip (in image above, drag the right edge of the track shown in V1 to the left). It now looks like this:
  4. Press Ctrl + Z to undo this trim…it’s broken! It does not go back to original state. Track in V2 is now missing. It looks like this:

Desired behavior: Undo should return to the previous state, but it doesn’t. I’m not sure what it’s doing exactly.

Note: the fact that track V1 was originally selected (highlighted yellow) before the action made no difference. I just duplicated the bug with track V2 selected the whole time.

Work-around: the work-around I use to get around this is I save often. Before making an edit with both ripple buttons active, I copy and paste a backup of my file. Then, I make the change. Since I can’t undo the change with the broken undo feature, I just re-open my backed-up file in case things go wrong.

Also, @shotcut, do you prefer I write bug reports like this here or on GitHub? I have a few more I’ll add in separate posts.

I also have several feature requests I’ll add to the forum here in separate posts.