<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=583064) </details> <!--IssueSummary end--> We don't update the cache key for the `diffs_batch.json` endpoint for Merge Requests when diff has conflicts. This causes for the 'Changes' tab to show irrelevant results without the conflicts. To reproduce: 1. Create a branch with changes 2. Create a merge requests for that branch 3. Open the 'Changes' tab, observe changes 4. Change the same lines in the target branch 5. Refresh the 'Changes' tab 6. Observe no conflicts in the diff 7. Observe `diffs_batch.json` response coming from disk cache, not from the server {width=900 height=426}