On Mon, May 1, 2017 at 9:04 PM, Stefan Beller <sbeller@xxxxxxxxxx> wrote:
>>
>>> I don't know why submodules were originally designed to be in a
>>> detached HEAD state but I much prefer working on branches (as I'm sure
>>> many other developers do) so the prospect of this becoming the norm is
>>> exciting! :D
>>
>
> I'll think about this more.
What the current model is missing is the possibility to have
a symbolic link not just to a ref within a repository, but to the outside
of a repository (such as the superproject in this case).
So we could have a HEAD with a content like:
"super: <superprojects git dir> [LF <path inside superproject>]"
Then we would use the HEAD to determine if the superproject
would touch a submodule at all. Example workflow:
git -C <sub> checkout --reattach-to-superproject
# hack away in the submodule
# This will make a commit in <sub> and add the
# resulting object to the index of the superproject
# because HEAD is tracking the superproject.
# so in order to have HEAD containing the new
# commit we have to change the superproject:
git -C <sub> commit -a -m "message"
# This has also interesting consequences for
# submodule related commands:
git checkout --recurse-submodules <tree-ish>
# Any submodule whose HEAD is attached to the
# superproject would be touched, the others would
# not.
By being directly attached to the superproject, it would be
easy to find all submodules that are changed, via a
git -C <super> status # no need to recurse, even!
The whole "checkout --recurse-submodules" series is based on
assumptions of the current mental model of how branches and
detached HEADs work.
A submodule would have a symref