Re: git-tag bug? confusing git fast-export with double tag objects

[Alex Riesen <raa.lkml@gmail.com>]

2009/5/14 Matthias Andree <matthias.andree@gmx.de>:
> Am 14.05.2009, 05:18 Uhr, schrieb Junio C Hamano <gitster@pobox.com>:
>> No.  You can tag any object, and a tag is an object.  You can point a
>> signed tag with your own signed tag to attest your own belief on that
>> other guy's tag, be it "it's genuine", "the tagged commit suits my need",
>> etc.
>
> OK, so I can tag/sign any object, fine.
>
> HOWEVER, I see two problems here (yes, they are corner cases):
>
> #1: git tag -f ("replace tag") fails to "replace" a heaviweight tag if I try
> to replace a tag by itself (or create a cycle by some other means).

It is not a "cycle" ("loop"?) The tags information is the SHA1, not
the tag's name.

> The new "foo" is unique in refs (OK), but it's *not unique* in objects
> (FAIL), as the old "foo" is referenced by the new "foo" and bears the same
> tag name.

Of course it is unique. Look at tag's SHA1.

> #2: related: git tag -d cannot reliably delete tag objects
>
> Same here: if another tag object references the tag object I'm deleting, we
> only delete the ref, but not the tag object. It doesn't (cannot) become
> dangling.

As soon as an object is not referenced anymore by any reference (including
references from refs/tags/), reference log or index it will be removed by
garbage collection (gc, prune) at the next opportunity.