Re: [PATCH] RFC: A new type of symbolic refs

Stefan Beller [off-list ref] writes:

quoted

Even if we limit ourselves to pointing at the index of the
superproject, there probably are a handful of interesting issues
that need to be clarified (not in the sense of "this and that issues
exist, so this won't be a useful feature", but in the sense of "we'd
be able to do these useful things using this feature, and we need to
fill in more details"), such as:

 - Making new commits in the submodule available to the upstream.
   Just like a detached HEAD in the submodule, this is not tied to
   any concrete branch, and it is unclear how a recursive "push"
   from the superproject should propagate the changes to the
   upstream of the submodule;

In Gerrit land people are trained to use
  git push HEAD:refs/for/master
which would work fine when propagated to the submodule as-is.

What I was alluding to is how you find 'master' in 'for/master',
given the submodule HEAD which only says "I point at the index of
the superproject".  Note that 'master' here refers to a branch
in the submodule.  If we further limit ourselves and declare that
a submodule that uses this external-reference as HEAD must always
be on the same branch as the superproject is on, then we can find
what branch the superproject is on, and use that.