oliverpool cb7ba8969d
fix: release page for empty or non-existing target (#24659)
Backport #24470

Fixes #24145

---

To solve the bug, I added a "computed" `TargetBehind` field to the
`Release` model, which indicates the target branch of a release. This is
particularly useful if the target branch was deleted in the meantime (or
is empty).

I also did a micro-optimization in `calReleaseNumCommitsBehind`. Instead
of checking that a branch exists and then call `GetBranchCommit`, I
immediately call `GetBranchCommit` and handle the `git.ErrNotExist`
error.

This optimization is covered by the added unit test.

_contributed in the context of @forgejo_
2023-05-12 14:14:41 -04:00
..