Edit conflict resolution needs to take into consideration all slots. Extra slots must not be ignored, otherwise edits may be silently overwritten.
Edit conflict resolution has two stages, which need to be considered and implemented separately:
- automatic conflict resolution via a 3-way-merge
- in case of merge conflicts, used mediated interactive resolution.
To fully satisfy this ticket, mediated interactive resolution has to work for all slots, and has to work for edits that change multiple slots at once. However, as a temporary base line, it may be acceptable to only implement automatic resolution multi-slot and non-main-slot edits, and reject the edit if automatic merging fails.