On 2020-05-07 at 19:42:24, Jeff King wrote:
> On Wed, May 06, 2020 at 08:16:35PM +0200, clime wrote:
> > Is something like that possible?
> > Is something like that possible even with git 1.7.1?
> 
> You'd need v1.7.2 for --ancestry-path. You could just use "$ref..HEAD"
> without it, and instead do:
> 
>   git merge-base --is-ancestor $ref HEAD
> 
> to cover the case where they aren't reachable from HEAD. But of course
> that's an extra traversal per tag.

I believe git merge-base --is-ancestor is much newer than v1.7.1.  I
think you have to use the old style, which IIRC is this:

  test "$(git rev-parse "$ref")" = "$(git merge-base "$ref" HEAD)"

If you'd like a more modern version for CentOS 6, I think Software
Collections has one with suitable support.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204