refs: extract out `refs_create_refdir_stubs()`

For Git to recognize a directory as a Git directory, it requires the
directory to contain:

  1. 'HEAD' file
  2. 'objects/' directory
  3. 'refs/' directory

Here, #1 and #3 are part of the reference storage mechanism,
specifically the files backend. Since then, newer backends such as the
reftable backend have moved to using their own path ('reftable/') for
storing references. But to ensure Git still recognizes the directory as
a Git directory, we create stubs.

There are two locations where we create stubs:

- In 'refs/reftable-backend.c' when creating the reftable backend.
- In 'clone.c' before spawning transport helpers.

In a following commit, we'll add another instance. So instead of
repeating the code, let's extract out this code to
`refs_create_refdir_stubs()` and use it.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 12 deletions

diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index fe74af73af..d8651fe779 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -491,18 +491,8 @@ static int reftable_be_create_on_disk(struct ref_store *ref_store,
 	safe_create_dir(the_repository, sb.buf, 1);
 	strbuf_reset(&sb);
 
-	strbuf_addf(&sb, "%s/HEAD", refs->base.gitdir);
-	write_file(sb.buf, "ref: refs/heads/.invalid");
-	adjust_shared_perm(the_repository, sb.buf);
-	strbuf_reset(&sb);
-
-	strbuf_addf(&sb, "%s/refs", refs->base.gitdir);
-	safe_create_dir(the_repository, sb.buf, 1);
-	strbuf_reset(&sb);
-
-	strbuf_addf(&sb, "%s/refs/heads", refs->base.gitdir);
-	write_file(sb.buf, "this repository uses the reftable format");
-	adjust_shared_perm(the_repository, sb.buf);
+	refs_create_refdir_stubs(the_repository, refs->base.gitdir,
+				 "this repository uses the reftable format");
 
 	strbuf_release(&sb);
 	return 0;