[PATCH v6 3/5] submodule: record superproject gitdir during absorbgitdirs

[Emily Shaffer <emilyshaffer@google.com>]

Already during 'git submodule add' we record a pointer to the
superproject's gitdir. However, this doesn't help brand-new
submodules created with 'git init' and later absorbed with 'git
submodule absorbgitdirs'. Let's start adding that pointer during 'git
submodule absorbgitdirs' too.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 submodule.c                        | 23 +++++++++
 t/t7412-submodule-absorbgitdirs.sh | 82 +++++++++++++++++++++++++++++-
 2 files changed, 103 insertions(+), 2 deletions(-)

diff --git a/submodule.c b/submodule.c
index c689070524..d7395c7551 100644
--- a/submodule.c
+++ b/submodule.c
@@ -2097,6 +2097,9 @@ static void relocate_single_git_dir_into_superproject(const char *path)
 	char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
 	struct strbuf new_gitdir = STRBUF_INIT;
 	const struct submodule *sub;
+	struct config_set sub_cs;
+	struct strbuf config_path = STRBUF_INIT, sb = STRBUF_INIT;
+	int tmp;
 
 	if (submodule_uses_worktrees(path))
 		die(_("relocate_gitdir for submodule '%s' with "
@@ -2127,6 +2130,26 @@ static void relocate_single_git_dir_into_superproject(const char *path)
 
 	relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
 
+	/*
+	 * Note location of superproject's gitdir. Because the submodule already
+	 * has a gitdir and local config, we can store this pointer from
+	 * worktree config to worktree config, if the submodule has
+	 * extensions.worktreeConfig set.
+	 */
+	strbuf_addf(&config_path, "%s/config", real_new_git_dir);
+	git_configset_init(&sub_cs);
+	git_configset_add_file(&sub_cs, config_path.buf);
+	/* return 0 indicates config was found - we have a worktree config */
+	if (!git_configset_get_bool(&sub_cs, "extensions.worktreeConfig", &tmp))
+		strbuf_addstr(&config_path, ".worktree");
+
+	git_config_set_in_file(config_path.buf, "submodule.superprojectGitdir",
+			       relative_path(absolute_path(get_git_dir()),
+					     real_new_git_dir, &sb));
+
+	git_configset_clear(&sub_cs);
+	strbuf_release(&config_path);
+	strbuf_release(&sb);
 	free(old_git_dir);
 	free(real_old_git_dir);
 	free(real_new_git_dir);
diff --git a/t/t7412-submodule-absorbgitdirs.sh b/t/t7412-submodule-absorbgitdirs.sh
index 1cfa150768..5753f90268 100755
--- a/t/t7412-submodule-absorbgitdirs.sh
+++ b/t/t7412-submodule-absorbgitdirs.sh
@@ -30,7 +30,17 @@ test_expect_success 'absorb the git dir' '
 	git status >actual.1 &&
 	git -C sub1 rev-parse HEAD >actual.2 &&
 	test_cmp expect.1 actual.1 &&
-	test_cmp expect.2 actual.2
+	test_cmp expect.2 actual.2 &&
+
+	# make sure the submodule cached the superproject gitdir correctly
+	submodule_gitdir="$(git -C sub1 rev-parse --path-format=absolute --git-common-dir)" &&
+	superproject_gitdir="$(git rev-parse --path-format=absolute --git-common-dir)" &&
+
+	test-tool path-utils relative_path "$superproject_gitdir" \
+		"$submodule_gitdir" >expect &&
+	git -C sub1 config submodule.superprojectGitDir >actual &&
+
+	test_cmp expect actual
 '
 
 test_expect_success 'absorbing does not fail for deinitialized submodules' '
@@ -61,7 +71,16 @@ test_expect_success 'absorb the git dir in a nested submodule' '
 	git status >actual.1 &&
 	git -C sub1/nested rev-parse HEAD >actual.2 &&
 	test_cmp expect.1 actual.1 &&
-	test_cmp expect.2 actual.2
+	test_cmp expect.2 actual.2 &&
+
+	sub1_gitdir="$(git -C sub1 rev-parse --path-format=absolute --git-common-dir)" &&
+	sub1_nested_gitdir="$(git -C sub1/nested rev-parse --path-format=absolute --git-common-dir)" &&
+
+	test-tool path-utils relative_path "$sub1_gitdir" "$sub1_nested_gitdir" \
+		>expect &&
+	git -C sub1/nested config submodule.superprojectGitDir >actual &&
+
+	test_cmp expect actual
 '
 
 test_expect_success 're-setup nested submodule' '
@@ -130,4 +149,63 @@ test_expect_success 'absorbing fails for a submodule with multiple worktrees' '
 	test_i18ngrep "not supported" error
 '
 
+test_expect_success 'absorbgitdirs works when called from a superproject worktree' '
+	# set up a worktree of the superproject
+	git worktree add wt &&
+	(
+	cd wt &&
+
+	# create a new unembedded git dir
+	git init sub4 &&
+	test_commit -C sub4 first &&
+	git submodule add ./sub4 &&
+	test_tick &&
+
+	# absorb the git dir
+	git submodule absorbgitdirs sub4 &&
+
+	# make sure the submodule noted the superproject gitdir correctly
+	submodule_gitdir="$(git -C sub4 rev-parse --absolute-git-dir)" &&
+	superproject_gitdir="$(git rev-parse --absolute-git-dir)" &&
+
+	test-tool path-utils relative_path "$superproject_gitdir" \
+		"$submodule_gitdir" >expect &&
+	git -C sub4 config submodule.superprojectGitDir >actual &&
+
+	test_cmp expect actual
+	)
+'
+
+test_expect_success 'absorbgitdirs works with a submodule with worktree config' '
+	# reuse the worktree of the superproject
+	(
+	cd wt &&
+
+	# create a new unembedded git dir
+	git init sub5 &&
+	test_commit -C sub5 first &&
+	git submodule add ./sub5 &&
+	test_tick &&
+
+	# turn on worktree configs for submodule
+	git -C sub5 config extensions.worktreeConfig true &&
+
+	# absorb the git dir
+	git submodule absorbgitdirs sub5 &&
+
+	# make sure the submodule noted the superproject gitdir correctly
+	submodule_gitdir="$(git -C sub5 rev-parse --absolute-git-dir)" &&
+	superproject_gitdir="$(git rev-parse --absolute-git-dir)" &&
+
+	test-tool path-utils relative_path "$superproject_gitdir" \
+		"$submodule_gitdir" >expect &&
+	git -C sub5 config submodule.superprojectGitDir >actual &&
+
+	test_cmp expect actual &&
+
+	# make sure the config went into the submodule config.worktree
+	test_file_not_empty "$submodule_gitdir/config.worktree"
+	)
+'
+
 test_done
-- 
2.34.0.rc1.387.gb447b232ab-goog