Re: [PATCH] checkout: allow full refnames for local branches

["Shawn O. Pearce" <spearce@spearce.org>]

Lars Hjemli <hjemli@gmail.com> wrote:
> I'm playing around with a gui frontend, and there I use
> git-for-each-ref to obtain possible arguments for git-checkout. That's
> how I discovered the 'problem', and solved it by stripping
> 'refs/heads/' in my frontend. But then I thought it would be nice if
> 'git-checkout' did the stripping on my behalf, since this might bite
> others too :)

If you are building "porcelain" to sit over Git and offer up a pretty
view of things, I would encourage you to avoid the stock porcelain.
Don't use git-checkout, its stock porcelain.  Instead go right to
the plumbing.  The plumbing doesn't really change behavior as often
(if ever).

You can see in git-checkout.sh what actions you need to perform,
but its really quite simple if there's no file-level merge involved.
Here's the relevent bits from git-gui:

    set cmd [list git read-tree]
    lappend cmd -m
    lappend cmd -u
    lappend cmd --exclude-per-directory=.gitignore
    lappend cmd $HEAD
    lappend cmd $new_branch
    set fd_rt [open "| $cmd" r]
    fconfigure $fd_rt -blocking 0 -translation binary
    fileevent $fd_rt readable \
        [list switch_branch_readtree_wait $fd_rt $new_branch]

    ...
    git symbolic-ref HEAD "refs/heads/$new_branch"

Really all I'm doing is building up an argument list for git
read-tree, passing it the commit that is currently in HEAD and the
commit I want to switch to ($new_branch), and then I wait for it
to finish its job.  When its done, I run git symbolic-ref to update
the current branch name.

-- 
Shawn.