"Active reviews" for a project forever includes proposals for unmarked abandoned branches

[Matthew Paul Thomas]

1. Have person X make a branch of a project.
2. Have person Y submit a merge proposal to person X's branch.
3. Have persons X and Y retire, die, or become hermits, without resolving the merge proposal beforehand.
4. Go to the project's "Active reviews" page.

What happens: The spurious merge proposal stays on the page forever, annoying remaining contributors.

This happened with <https://code.launchpad.net/developer-ubuntu-com/+activereviews>. When a contributor left, my merge proposal for one of their branches was left unresolved. I could remove it, three years later, only because I happened to still be around.

What should happen: The project should not have an "Active reviews" page in the first place. In any sufficiently popular project, it will gradually accumulate abandoned merge proposals on abandoned branches that, for whatever reason, weren't marked as such.

Instead, the list of active reviews for the trunk branch should be as prominent as the aggregated list is now. For the trunk, if one maintainer does not deal with a merge proposal before leaving, the next maintainer can. For an abandoned branch, the list of active reviews can happily remain non-empty forever because nobody will look at it any more.

The presentation of this, on the project Code page, could be replacing the "{project} has {number} active reviews" line with an "Active reviews" column in the table of branches.