Re: [RFC/PATCH] add update to branch support for "floating submodules"

[Phil Hord <phil.hord@gmail.com>]

On Mon, Dec 12, 2011 at 2:13 PM, Leif Gruenwoldt <leifer@gmail.com> wrote:
> On Mon, Dec 12, 2011 at 1:42 PM, Andreas T.Auer
> <andreas.t.auer_gtml_37453@ursus.ath.cx> wrote:
>
>> The next question is: Wouldn't you like to have the new stable branch only
>> pulled in, when the projectX (as the superproject) is currently on that new
>> development branch (maybe master)?
>>
>> But if you checkout that fixed released version 1.2.9.8, wouldn't it be
>> better that in that case the gitlinked version of the submodule is checked
>> out instead of some unrelated new version? I mean, when the gitlinks are
>> tracked with the projectX commits, this should work well.
>>
>> And what about a maintenance branch, which is not a fixed version but a
>> quite stable branch which should only have bugfixes. Shouldn't the auto-pull
>> be disabled in that case, too?
>>
>> I think the "auto-pull" behavior should depend on the currently checked out
>> branch. So the configuration options should allow the definition of one or
>> more mappings.
>
> Yes. I think you nailed it. The floating behaviour would best be
> configured per branch.

Yes, I think you nailed it too.  I've been thinking the same thing for
a while now, but I didn't know how to express it completely.  Some of
the discussion on here last week gelled the last bits in my mind.

To wit, I think I would want something like this in my project:

Use gitlinks when the superproject HEAD is one of these:
    refs/heads/maint/*
    refs/heads/svn/*     (historic branches)
    refs/tags/*
    <SHA1> (detached)

Float on the rest, using the branch given in .gitmodules (which may be
* to mean "use the same branch as the superproject".)

But maybe it is foolish of me to keep branches where I really want
lightweight tags.  If so, I could get away with this:

   Float if .git/HEAD begins with "refs/heads"
   Else, use the SHA1.


> An aside. Would this mean a "git pull" on the product repo would
> automatically do a pull (git submodule update) on the submodule too?

Good question.

I want to say "eventually, but not yet."  But someone else may
disagree.  "git pull --recurse-submodules=yes" does not do this yet.
A separate git-submodule-update is still required.  But I think this
is a separate issue from floating submodules.

Phil