Re: branch tracking: inherit upstream

> At work, our primary SCM is perforce (p4), but many of us use git
> in front of that for day-to-day work.  The build system requires
> information about what part of the P4 repository it is building.
> I've cobbled together changes to make this work with git, and
> have been using "git merge-base HEAD @{upstream}" to find the
> top-most git-p4 commit.
>
> But @{upstream} is not automatically inherited by branches.  It
> is fine when a local branch is a normal tracking branch of
> origin/master, like:
>
>    $ git checkout master
>    $ git rev-parse --symbolic-full-name @{upstream}
>    refs/remotes/origin/master
>
> But I'd also like this to work:
>
>    $ git branch feature
>    $ git checkout feature
>    $ git rev-parse --symbolic-full-name @{upstream}
>    error: No upstream branch found for ''
>    @{upstream}
>    error: No upstream branch found for ''
>    fatal: ambiguous argument '@{upstream}': unknown revision or path not in the working tree.
>    Use '--' to separate paths from revisions
>
> I know I can do:
>
>    $ git branch --set-upstream feature origin/master
>
> but that is a pain.  And I know I can track the local master, but
> that is not what I want.
>
> I'm looking for something like "branch.autosetupupstream" that
> would cause the upstream of new branches to be copied from the
> old branch (when it exists).  Does this make sense?