Re: [RFC PATCH 4/4] submodule: cache superproject gitdir during 'update'

> 
> Emily Shaffer <emilyshaffer@google.com> writes:
> 
> > A cached path to the superproject's gitdir might be added during 'git
> > submodule add', but in some cases - like submodules which were created
> > before 'git submodule add' learned to cache that info - it might be
> > useful to update the cache. Let's do it during 'git submodule update',
> > when we already have a handle to the superproject while calling
> > operations on the submodules.
> >
> > Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> > ---
> >  git-submodule.sh            |  9 +++++++++
> >  t/t7406-submodule-update.sh | 10 ++++++++++
> >  2 files changed, 19 insertions(+)
> >
> > diff --git a/git-submodule.sh b/git-submodule.sh
> > index eb90f18229..ddda751cfa 100755
> > --- a/git-submodule.sh
> > +++ b/git-submodule.sh
> > @@ -648,6 +648,15 @@ cmd_update()
> >  			fi
> >  		fi
> >  
> > +		# Cache a pointer to the superproject's gitdir. This may have
> > +		# changed, so rewrite it unconditionally. Writes it to worktree
> > +		# if applicable, otherwise to local.
> > +
> > +		sp_gitdir="$(git rev-parse --absolute-git-dir)"
> > +		relative_gitdir="$(realpath --relative-to "$sm_path" "$sp_gitdir")"
> 
> realpath may not exist on the target system.  Discussions on the
> patch [*1*] may be of interest.
> 
> It might be a good idea to push to your github repository to trigger
> CI on macOS (I am guessing that you do not test locally on macs from
> the two issues we saw in this series).

> 
> Thanks.
> 
> 
> [Reference]
> 
> *1*
> https://lore.kernel.org/git/20201206225349.3392790-3-sandals@crustytoothpaste.net/