Undoing A 1 Frame Transition Can Delete Clip

[DRM]

Bring a clip to the timeline. Delete a few seconds or minutes from the start of the clip. Then split the clip and bring the first half (clip A) to the end of the second half (clip B). Grab the start of clip A and drag it to the end of clip B to make a one frame transition. After that, undo it. Instead of undoing the transition clip B will be deleted and the transition clip along with clip A will be pushed back. Demo.

This has happened to me many times for a long time now but it is only recently that I seemingly have found the trigger for it. It’s quite common for me because I will sometimes by accident create a one frame transition when dragging the end of clips and then this very annoying bug happens.

[shotcut]

This is fixed for the next version 21.02.
What was interesting is that if you, while still dragging, had made a transition duration > 1 and then reduced it to 1, the bug does not occur. Let this serve as a reminder that you do not have be to be exact and drag in only one direction, and that is a workaround until you have the fix.