Created attachment 180663 [details]
Strange transition created after moving clip to the right

SUMMARY
This may not be a problem that many people might encounter, but I found it while testing recent changes from master builds. What might be most problematic is the part of not being able to delete the longer transitions being created.

STEPS TO REPRODUCE
1. Have a 1-minute long MPEG clip cut into three parts (creating 5 smaller clips in total)
2. Select clip 2 and 4 and press the "u" key to create a transition
3. Drag clip 4 and place it after clip 5

OBSERVED RESULT
Dragging clip to the right creates some kind of long transition extending from clip 5 to clip 4, at least in appearance, but one cannot delete it as normally done with the Del key. The original uncut clip in the Project Bin cannot be deleted either, with Kdenlive complaining about locking. Pressing Ctrl+Z a few times to undo these might crash Kdenlive.

EXPECTED RESULT
Clip 4 should not inherit the transition to clip 5 when dragged at any new place in the timeline. 

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION