Re: best way to fastforward all tracking branches after a fetch

From: Sitaram Chamarty <sitaramc@gmail.com>
Date: Dec 11, 2011, 18:56 UTC
Message-ID: <CAMK1S_gjZSBv5ASz4GhV25TsRKuzBvZ9D7_X+bniP9K0BQQCmA@mail.gmail.com>
In-Reply-To: <m3ehwbge8f.fsf@localhost.localdomain>

2011/12/11 Jakub Narebski <jnareb@gmail.com>:

Show 37 quoted lines

> Don't remove people from Cc, please.
>
> Gelonida N <gelonida@gmail.com> writes:
>> On 12/11/2011 03:22 AM, Sitaram Chamarty wrote:
>> > On Sat, Dec 10, 2011 at 01:26:32PM +0100, Gelonida N wrote:
>
>> > So what you want would boil down to this script (untested):
>> >
>> >     #!/bin/bash
>> >     git status --porcelain -uno | grep . && {echo dirty tree, exiting...; exit 1; }
>> >
>> >     for b in `git for-each-ref '--format=%(refname:short)' refs/heads`
>> >     do
>> >         git checkout $b
>> >         git merge --ff-only @{u}
>> >     done
>>
>> Is there no way to distinguish tracking branches from other branches?
>> without checking them out?
>>
>> In order to save time I'd like to avoid checking out local branches.
>
> You can use 'upstream' field name in git-for-each-ref invocation,
> for example
>
>  git for-each-ref '--format=%(refname:short) %(upstream:short)' refs/heads |
>        grep -e ' [^ ]' |
>        sed  -e 's/ .*$//
>
> This could probably be done using only sed -- grep is not necessary.
>
>> Ideally I would even like to avoid checking out branches, which don't
>> need to be forwarded.
>
> You can use git-update-ref plumbing, but you would have to do the
> check if it does fast-forward yourself, and provide reflog message
> yourself too.

if it's not the currently checked-out branch, 'git branch -f foo origin/foo' seems to work fine. However, it only updates the branch reflog, not the HEAD reflog also, naturally.

FWIW...

Show 36 quoted lines

> Something like
>
>  git for-each-ref '--format=%(refname) %(upstream)' |
>  while read refname upstream
>  do
>        # there is upstream
>        test -n "$upstream" || break
>        # and if fast-forwards
>        test $(git merge-base $refname $upstream) = $(git rev-parse $refname) || break
>        git update-ref -m "$message" $refname $upstream
>  done
>
>> I also had to remember on which branch I was in order to avoid, that I
>> am at a random branch after running the script.
>>
>> I could imagine something like my snippet below , though I guess,
>> there's something more elegant.
>>
>> git stash
>> mybranch=`git branch | sed -n 's/\* *//p'`
>> # do_script . . .
>> git checkout $mybranch
>> git stash apply
>
> Don't use git-branch in scripting.  See __git_ps1 function in
> contrib/completion/git-completion.bash how it can be done:
>
>  b="$(git symbolic-ref HEAD 2>/dev/null)" ||
>  b="$(git rev-parse --verify HEAD)"
>
> Nb. the second part is here only if there is possibility that you are
> on detached HEAD (unnamed branch).
>
> HTH (hope that helps)
> --
> Jakub Narębski

-- 
Sitaram