Transition types get reset at render time
Tested with current master flatpak build:
- I imported two quicktime clips, let it generate fast (scaled) proxies, inserted them in the timeline.
- I made them cross each other to create a transition.
- I clicked the transition, set it to be normal "diagonal-tl" (the diagonal wipe top-left to bottom-right) with smoothing.
- Render (in my case to mp4 with x264)
- Inspect the resulting video, notice the transition is a crossfade instead of diagonal-tl
- Inspect the transition in the timeline in Pitivi again, and indeed it has changed to crossfade in the UI.