Re: git fetch refs and tags

> Am Dienstag, den 23.04.2013, 13:25 +0200 schrieb Johan Herland:
>> On Tue, Apr 23, 2013 at 12:53 PM, Jan Weitzel <J.Weitzel@phytec.de> wrote:
>> > Hello,
>> > I have the following problem: I have 2 bare git repositories one has
>> > several branches and tags.
>> > If I try this in the second repository:
>> > git fetch -f ../main.git refs/heads/master:refs/heads/master
>> > I'm getting also tags from other branches, if I have an old object from
>> > one of the other branches.
>> > I would expect to have only tags pointing to master ref. (Although the
>> > man pages points to the behaviour regarding dangling objects). Is there
>> > a way to avoid this? I only find --no-tags which results in having no
>> > tags at all. Or need I git purge to remove the old objects first?
>> > My goal is to fetch only specific branches and the related tags.
>>
>> AFAIK, Git should only auto-follow tags that are reachable from the
>> branches you fetch (in this case master). Are you saying that you get
>> tags pointing to other history that is NOT reachable from the master
>> branch? (i.e. are you getting tags for which "git merge-base $tag
>> master" is not equal to "git rev-parse $tag")?
>>
> exactly. I reproduced it by coping a object from an other branch to the
> locale repository. This results in fetching the not reachable tags.
>
>> Re-reading the man page, I do see the following:
>>
>> "if the repository has objects that are pointed by remote tags that it
>> does not yet have, then fetch those missing tags. If the other end has
>> tags that point at branches you are not interested in, you will not
>> get them."
>>
>> This can be interpreted as saying that even unreachable objects in
>> your local repo that are pointed to by some remote tag will cause that
>> tag to be fetched, and in effect resuscitate the
>> previously-unreachable object. If this is indeed how it works, I would
>> be tempted to label this a bug in the auto-following behavior, as it's
>> probably not what most people would expect. In that case, yes, you
>
> Yes my first understanding of auto-following behaviour was wrong ;)
>
>> should be able to get your desired behavior by first purging all
>> unreachable objects. Something like "git gc --prune=now" should do the
>> job.
>
> Because I run this by scripts is there a way without porcelain commands?
> I saw even git prune is one.