RE: [RFC] Branches with --recurse-submodules

[Glen Choo <chooglen@google.com>]

<rsbecker@nexbridge.com> writes:

>> > 4. If working on the submodule, use a branch, not a commit - typically off
>> main.
>> 
>> With the proposed UX, step (4) would happen automatically when using
>> "branch --recurse-submodules". Users would get a safer and more
>> convenient default.
>
> I think this might be more reliably done using a switch in .gitconfig to enable the capabilities. Perhaps something like:
>
> submodule.fetch-branches=true

Correct me if I am wrong, but we might be suggesting different things
here. "submodule.fetch-branches" suggests to me that you're thinking of
submodule branches that track the remotes of the submodule. The proposed
UX is more about how we have submodule branches that work in tandem with
superproject branches.

A user who is only concerned about a single submodule can cd and make
their changes as if the submodule were a standalone repo - I think
that's pretty well-supported. The missing link being able to coordinate
this work with the superproject.

>> > What I could see as a possible improvement is to add the branch ref to the
>> submodule ref file - not replacing the commit but adding to it. I do worry that
>> there are unintended (unforeseen) side-effects that will result from this,
>> however, including potential merge conflicts. Two people working on the
>> same commit but different branches may mess the ref file, so not really a
>> good idea.
>> 
>> It's an interesting idea, but as you noted, it is quite thorny. I would also like to
>> see more information being captured by the superproject tree (instead of
>> just .gitmodules), but I'm also not sure how we might do that.
>
> I'm suggesting this instead of a command-line option because this seems more like a policy-based process that you would either always want or never want. I would not like to depend on a developer making the call each time a clone occurred. I'm sad to admit that I don't really know where to start on this enhancement, though, even if approved.

Agreed with regards to both points, i.e. using a config instead of CLI
option, and not knowing where to start..