Re: [PATCH] fix sample update hook, disable overwriting of existing tags

Heiko Voigt [off-list ref] writes:

Because no special rule for this existed it was allowed by default

I do not disagree that it is a good thing to be able to reject
overwriting, but I do not think it is a _fix_.  allowdeletetag is about
_deletion_ and it already is covered by the code, isn't it?

I think it would make more sense to introduce $allowmodifytag and reject
such pushes in the codepath you touched.