When a PR reviewer reviewed a file on a commit that was later gc'ed,
they would always get a `500` response from then on when loading the PR.
This PR simply ignores that error and instead marks all files as
unchanged.
This approach was chosen as the only feasible option without diving into
**a lot** of error handling.
Fixes#21392
Backport of #21487
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Backport of #21230
The problem was that many PR review components loaded by `Show more`
received the same ID as previous batches, which confuses browsers (when
clicked). All such occurrences should now be fixed.
Additionally improved the background of the `viewed` checkbox.
Fixes#21228.
Fixes#20681.
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
