[PATCH 4/4] submodule--helper: use relative path if possible

[Stefan Beller <sbeller@google.com>]

As submodules have working directory and their git directory far apart
relative_path(gitdir, work_dir) will not produce a relative path when
git_dir is absolute. When the gitdir is absolute, we need to convert
the workdir to an absolute path as well to compute the relative path.

(e.g. gitdir=/home/user/project/.git/modules/submodule,
workdir=submodule/, relative_dir doesn't take the current working directory
into account, so there is no way for it to know that the correct answer
is indeed "../.git/modules/submodule", if the workdir was given as
/home/user/project/submodule, the answer is obvious.)

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 builtin/submodule--helper.c | 7 +++++++
 t/t7400-submodule-basic.sh  | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 914e561..0b0fad3 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -159,6 +159,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	FILE *submodule_dot_git;
 	char *sm_gitdir, *cwd, *p;
 	struct strbuf rel_path = STRBUF_INIT;
+	struct strbuf abs_path = STRBUF_INIT;
 	struct strbuf sb = STRBUF_INIT;
 
 	struct option module_clone_options[] = {
@@ -219,7 +220,12 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	if (!submodule_dot_git)
 		die_errno(_("cannot open file '%s'"), sb.buf);
 
+	strbuf_addf(&abs_path, "%s/%s",
+		    get_git_work_tree(),
+		    path);
 	fprintf(submodule_dot_git, "gitdir: %s\n",
+		is_absolute_path(sm_gitdir) ?
+		relative_path(sm_gitdir, abs_path.buf, &rel_path) :
 		relative_path(sm_gitdir, path, &rel_path));
 	if (fclose(submodule_dot_git))
 		die(_("could not close file %s"), sb.buf);
@@ -242,6 +248,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 			       relative_path(sb.buf, sm_gitdir, &rel_path));
 	strbuf_release(&sb);
 	strbuf_release(&rel_path);
+	strbuf_release(&abs_path);
 	free(sm_gitdir);
 	free(cwd);
 	free(p);
diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index fc11809..ea3fabb 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -818,7 +818,7 @@ test_expect_success 'submodule add --name allows to replace a submodule with ano
 	)
 '
 
-test_expect_failure 'recursive relative submodules stay relative' '
+test_expect_success 'recursive relative submodules stay relative' '
 	test_when_finished "rm -rf super clone2 subsub sub3" &&
 	mkdir subsub &&
 	(
-- 
2.5.0.264.g4004fdc.dirty