* Fix loading content history on show more
- Call `initRepoIssueContentHistory` so that the newly loaded issues
also get their content history.
- Resolves#17767
* apply history to show diff too
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>