Re: Potential bug in git client

[Michael Haggerty <mhagger@alum.mit.edu>]

On 06/11/2014 12:21 PM, Wojciech Przybył wrote:
> When I was tagging, I think I might have discovered a git client bug.
> [...]
> HOW TO REPRODUCE:
> - Clone a repo into 2 separate directories. Presume there is a tag
> "v0.1" already in there and it is set on say 10 commits ago.
> 
> - In first directory change the tag to a different place and push it
> to the server:
> git tag -d v0.1
> git tag v0.1
> git push --tags origin master
> 
> - In second directory try to update the tag...
> git pull --all --tags
> git fetch -all --tags
> THIS DOES NOT WORK, tag is still at old place, but it says "Already up-to-date".
> 
> - I noticed when I use:
> git fetch --tags
> it works fine and updates the position of the tag, or if I remove tag
> from local git manually (rm .git/refs/tags/v0.1) and update again.
> 
> Is it a bug or I am doing something wrong? I use git version 1.7.9.5.

Tag fetching changed quite a bit in v1.9.0.  Here is a similar test
using Git 2.0.0:

$ git init main
Initialized empty Git repository in /home/mhagger/tmp/tagexp/main/.git/
$ cd main
$ git commit --allow-empty -m Initial
[master (root-commit) fdcd35b] Initial
$ git tag t
$ git commit --allow-empty -m Second
[master 88f7d4a] Second
$ cd ..
$ git clone main clone1
Cloning into 'clone1'...
done.
$ git clone main clone2
Cloning into 'clone2'...
done.
$ cd clone1
$ git tag -d t
Deleted tag 't' (was fdcd35b)
$ git tag t
$ git push --tags origin master
To /home/mhagger/tmp/tagexp/main
 ! [rejected]        t -> t (already exists)
error: failed to push some refs to '/home/mhagger/tmp/tagexp/main'
hint: Updates were rejected because the tag already exists in the remote.

So, it is impossible to overwrite tags on the server by pushing with the
--tags option.  But we can use a force push:

$ git push origin +refs/tags/t
Total 0 (delta 0), reused 0 (delta 0)
To /home/mhagger/tmp/tagexp/main
 + fdcd35b...88f7d4a t -> t (forced update)
$ cd ../clone2
$ git pull --all --tags
Fetching origin
From /home/mhagger/tmp/tagexp/main
 - [tag update]      t          -> t
Already up-to-date.

So, the tag is now updated but with a visible display of what happened.
 Similarly with fetch:

$ git update-ref refs/tags/t HEAD^
$ git fetch --all --tags
Fetching origin
From /home/mhagger/tmp/tagexp/main
 - [tag update]      t          -> t

Is this closer to the behavior that you want?

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu