fix pulls broken when fork repository deleted

[lunny]

fix #6702

[lafriks]

Drone fail

[codecov-io]

Codecov Report

Merging #6754 into master will decrease coverage by 0.02%.
The diff coverage is 7.14%.

@@            Coverage Diff             @@
##           master    #6754      +/-   ##
==========================================
- Coverage   41.03%   41.01%   -0.03%     
==========================================
  Files         421      421              
  Lines       57955    57967      +12     
==========================================
- Hits        23781    23773       -8     
- Misses      31017    31035      +18     
- Partials     3157     3159       +2

Impacted Files	Coverage Δ
models/error.go	32.08% <0%> (-0.43%)	⬇️
models/pull.go	50.41% <0%> (-0.14%)	⬇️
routers/repo/issue.go	35.58% <20%> (-0.17%)	⬇️
modules/log/event.go	64.46% <0%> (-1.53%)	⬇️
routers/repo/view.go	42.02% <0%> (-1.02%)	⬇️

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[lafriks]

Where does it check for this new error?

[lunny]

@lafriks GetLastCommitStatus now will check if the headRepo exist or not, and will return new error ErrPullRequestHeadRepoMissing. The panic caused by unchecked headRepo nil.

[lafriks]

But shouldn't we check later for that error and show some kind of error in PR?

[lunny]

When list pull requests, the last commit status error could be ignored.

[lunny]

v1.8 don't have this problem.

[ntimo]

Is this going to be backported to 1.8? :)

[lunny]

v1.8 should not be affected by this issue.