submodule: extract path to submodule gitdir func

We currently store each submodule gitdir in ".git/modules/<name>", but
this has problems with some submodule naming schemes, as described in a
comment in submodule_name_to_gitdir() in this patch.

Extract the determination of the location of a submodule's gitdir into
its own function submodule_name_to_gitdir(). For now, the problem
remains unsolved, but this puts us in a better position for finding a
solution.

This was motivated, at $DAYJOB, by a part of Android's repo hierarchy
[1]. In particular, there is a repo "build", and several repos of the
form "build/<name>".

This is based on earlier work by Brandon Williams [2].

[1] https://android.googlesource.com/platform/
[2] https://lore.kernel.org/git/20180808223323.79989-2-bmwill@google.com/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/dir.c b/dir.c
index 03c4d21267..5fe5d3a42e 100644
--- a/dir.c
+++ b/dir.c
@@ -3633,7 +3633,7 @@ static void connect_wt_gitdir_in_nested(const char *sub_worktree,
 		strbuf_reset(&sub_wt);
 		strbuf_reset(&sub_gd);
 		strbuf_addf(&sub_wt, "%s/%s", sub_worktree, sub->path);
-		strbuf_addf(&sub_gd, "%s/modules/%s", sub_gitdir, sub->name);
+		submodule_name_to_gitdir(&sub_gd, &subrepo, sub->name);
 
 		connect_work_tree_and_git_dir(sub_wt.buf, sub_gd.buf, 1);
 	}