[PATCH v7 4/7] submodule: allow do_submodule_path to work if given gitdir directly

[Jacob Keller <jacob.e.keller@intel.com>]

From: Jacob Keller <jacob.keller@gmail.com>

Currently, do_submodule_path relies on read_gitfile, which will die() if
it can't read from the specified gitfile. Unfortunately, this means that
do_submodule_path will not work when given the path to a submodule which
is checked out directly, such as a newly added submodule which you
cloned and then "git submodule add". Instead, replace the call with
resolve_gitdir. This first checks to see if we've been given a gitdir
already.

Because resolve_gitdir may return the same buffer it was passed, we have
to check for this case as well, since strbuf_reset() will not work as
expected here, and indeed is not necessary.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
---
 path.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/path.c b/path.c
index 17551c483476..d1af029152a2 100644
--- a/path.c
+++ b/path.c
@@ -477,8 +477,8 @@ static void do_submodule_path(struct strbuf *buf, const char *path,
 	strbuf_complete(buf, '/');
 	strbuf_addstr(buf, ".git");
 
-	git_dir = read_gitfile(buf->buf);
-	if (git_dir) {
+	git_dir = resolve_gitdir(buf->buf);
+	if (git_dir && git_dir != buf->buf) {
 		strbuf_reset(buf);
 		strbuf_addstr(buf, git_dir);
 	}
-- 
2.10.0.rc0.217.g609f9e8.dirty