SUMMARY I have finally been able to duplicate the UI freeze reliably. STEPS TO REPRODUCE 1. Generate project with two video and two audio tracks 2. Add three sections of clips to the timeline 3. First clip to the bottom video track 4. Second clip to the top video track, overlapping first clip by a few frames 5. Third clip to the bottom video track, overlapping second clip by a few frames 6. Select top video clip, and add composition 7. Drag composition to align last frame to the last frame of the top video clip 8. Try to adjust the first frame of the composition by dragging the front of the composition on the timeline. OBSERVED RESULT UI freeze EXPECTED RESULT First frame to be adjusted with drag of mouse. SOFTWARE/OS VERSIONS Arch Linux updated 2019-02 ADDITIONAL INFORMATION
Created attachment 118312 [details] backtrace of the crash
Funny thing, kdenlive now crashes when I adjust the first frame of a composition after dragging it around. Good thing, as we now have a nice gdb crash log. It's a bit long, as I was dragging clips around, the first clip I dragged into the timeline the audio track would display blank, but that is not related to this bug, I hope. Have at it!
Fixed properly, thank you very much.