Bug 461655

SUMMARY
Context: Function "extract timeline zone" (Shift-X) removes a time zone selected by the Set-Zone-In, Set-Zone-Out tool. All tracks are effected by this removal and right side clips shift to left with the effected frames.
Bug: All tracks are effected but the subtitles track, where subtitles does not shifts with the removal. They loosing sync with this operation.


STEPS TO REPRODUCE
1. Prepare a track with a clip.
2. Add a subtitle(s) matching a specific part of the clip content (but not to the very beginning to the clip).
3. Select a time-zone left to the subtitle.
4. Apply "extract timeline zone" (Shift-X) tool.

OBSERVED RESULT
The some frames are removed from the clip and right side joins the left side by shifting to left, but the subtitle(s) does not do the shift, thus getting out of sync. The subtitle appears in a later position than it was intended to be.

EXPECTED RESULT
The subtitle should be handled as a separate track, and "extract timeline zone" should effect that track as well. And in this manner the removal should make subtitle(s) on the right to shift left accordingly and keep in sync with the other track(s).

SOFTWARE/OS VERSIONS
macOS: 11.7