When a clip in the timeline has (enabled) keyframable effects then a double click on the clip in the timeline doesn't bring up the "duration" dialog anymore. Instead, a double click adds a keyframe at the position of the double click. As long as any present keyframable effects on a clip are disabled, then the double click works again as expected. In any case, I would suggest to add "Edit duration" to the context menu for clips in the timeline. I don't think that this will make the context menu too complex, yet makes a function available that probably many users need for precise trimming. Reproducible: Always Steps to Reproduce: 1. In a new, empty project: add color clip (pick your own preferred color). 2. Drag color clip into timeline, select it. 3. Add effect "Brightness (keyframable)". 4. Double click on clip in timeline. Actual Results: A new keyframe is added to the effect. Expected Results: No keyframe is added; instead, the "duration" dialog should be shown.
Double click actually adds a keyframe on intention. So I'm closing this bug now, albeit I find the current UI behavior to be less than ideal as it is inconsistent: clips without keyframable effects behave different from those effects that do have keyframable effects on them.