View pull request 500

[lunny]

In a migrated repository, some pull request pages return 500 when view the page.

2020/01/21 20:53:09 ...vices/pull/update.go:67:GetDiverging() [T] PushToBaseRepo[11]: pushing commits to base repo 'refs/pull/661/head'
2020/01/21 20:53:09 routers/repo/pull.go:348:PrepareViewPullInfo() [E] GetDiverging: exit status 128 - fatal: ambiguous argument 'master..unknown repository': unknown revision or path not in the working tree.
	Use '--' to separate paths from revisions, like this:
	'git <command> [<revision>...] -- [<file>...]'
	
2020/01/21 20:53:09 ...s/context/context.go:139:HTML() [D] Template: status/500

[6543]

think this is caused by #9784

look's like a reference is missing :(

maby GetDiverging Link should check if HeadBranch != "" ? but this should be not be the case for a correct PR either ...

[6543]

so maby there is a issue with migration witch drop some needed information

[6543]

@lunny how to reproduce?

[lunny]

The head repository or head branch maybe deleted before merged. I think that's the problem. This should be a regression.