Re: [RFC v2] submodule: Respect requested branch on all clones

"W. Trevor King" [off-list ref] writes:

On Tue, Jan 07, 2014 at 10:15:25AM -0800, Junio C Hamano wrote:

quoted

    submodule: respect requested branch on all clones

    The previous code only checked out the requested branch in cmd_add
    but not in cmd_update; this left the user on a detached HEAD after
    an update initially cloned, and subsequent updates using rebase or
    merge mode will kept the HEAD detached, unless the user moved to the
    desired branch himself.

    Move the branch-checkout logic into module_clone, where it can be
    shared by cmd_add and cmd_update.  Also update the initial checkout
    command to use 'rebase' to preserve branches setup during
    module_clone.  This way, unless the user explicitly asks to work on
    a detached HEAD, subsequent updates all happen on the specified
    branch, which matches the end-user expectation much better.

This looks reasonable to me, but there are still changes I'd like to
make for a v3 (e.g. using submodule.<name>.update to trigger local
branch checkout).  However, I'm currently leaning towards a new 'git
submodule checkout' command with explicit preferred local submodule
branches (see [1]).  Maybe this should all wait until Jens rolls out
his update implementation [2]?

Sounds good.  I'll backburner this one, then.

quoted

Having writing all the above and then looking at the patch again, it
is not immediately obvious to me where you use "rebase" when doing
the initial checkout, though.

It's used to shift the local branch reference from from the
(arbitrary) cloned remote branch tip to the explicit submodule $sha1.

The objective is not what I was questioning. In the patch I see

	git checkout -f -q -B "$branch" "origin/$branch"

used in the module_clone (which I think makes sense), and then
cmd_update uses "git reset --hard -q" to make sure that the working
tree matches the commit $sha1 obtained from the superproject's
gitlink (which may make $branch diverged from origin/$branch, but
still I think it makes sense).

But there is no 'rebase' I can see in the codepath, which was what I
was puzzled about.