Re: [PATCH] describe: dont abort too early when searching tags

> When searching the commit graph for tag candidates, `git-describe`
> will stop as soon as there is only one active branch left and
> it already found an annotated tag as a candidate.
>
> This works well as long as all branches eventually connect back
> to a common root, but if the tags are found across branches
> with no common ancestor
>
>                   B
>                   o----.
>                         \
>           o-----o---o----x
>           A
>
> it can happen that the search on one branch terminates prematurely
> because a tag was found on another, independent branch. This scenario
> isn't quite as obscure as it sounds, since cloning with a limited
> depth often introduces many independent "dead ends" into the commit
> graph.
>
> The help text of `git-describe` states pretty clearly that when
> describing a commit D, the number appended to the emitted tag X should
> correspond to the number of commits found by `git log X..D`.