Re: git branch --set-upstream regression in master

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 16, 2011, 22:58 UTC
Message-ID: <7v7h58dri4.fsf@alter.siamese.dyndns.org>
In-Reply-To: <CAG+J_DyxNpPevwfrJVkv3GBmv0tEXgW2LZtdHgarFoXb9Qqghw@mail.gmail.com>

Jay Soffian <jaysoffian@gmail.com> writes:

Show 9 quoted lines

> This used to be possible on the checked out branch:
>
>   $ git branch master --set-upstream origin/master
>
> Now it gives "fatal: Cannot force update the current branch." which is
> broken. You should be able to setup/change the tracking information on
> the checked out branch.
>
> It's apparently due to ci/forbid-unwanted-current-branch-update.

Does

	git branch --set-upstream master origin/master

work? If so then I wouldn't worry too much about it (your "arg then option" should be forbidden in the longer term anyway). If not, we would need to patch it.

Show 5 quoted lines

> (BTW, --set-upstream still needs to be fixed so that these mean the same
> thing:
>
>   $ git branch master --set-upstream origin/master
>   $ git branch --set-upstream origin/master master

If we are doing anythning, I think it needs to be fixed not to allow the former, period.

Show 5 quoted lines

> .. to just allow:
>
>   $ git branch --set-upstream origin/master
>
> w/o having to specify the checked-out branch.

That may be a nice feature enhancement, post 1.7.7 release.

I took a brief look at --set-upstream codepath, and I have to say that the implementation is totally broken with respect to an existing branch.

Given

	$ git branch master --set-upstream origin/master

it passes the exact same codepath as

	$ git branch master origin/master

uses, only with a different "track" flag, no? That is, it calls a function that is meant to _create_ branch "master" from given branch point "origin/master", namely create_branch(). And then create_branch(), contrary to its name, is littered with "dont_change_ref" special case to work it around, depending on the value of "track".