Revert "Merge branch 'sb/submodule-core-worktree'"

This reverts commit 7e25437d, reversing
changes made to 00624d60.

v2.19.0-rc0~165^2~1 (submodule: ensure core.worktree is set after
update, 2018-06-18) assumes an "absorbed" submodule layout, where the
submodule's Git directory is in the superproject's .git/modules/
directory and .git in the submodule worktree is a .git file pointing
there.  In particular, it uses $GIT_DIR/modules/$name to find the
submodule to find out whether it already has core.worktree set, and it
uses connect_work_tree_and_git_dir if not, resulting in

	fatal: could not open sub/.git for writing

The context behind that patch: v2.19.0-rc0~165^2~2 (submodule: unset
core.worktree if no working tree is present, 2018-06-12) unsets
core.worktree when running commands like "git checkout
--recurse-submodules" to switch to a branch without the submodule.  If
a user then uses "git checkout --no-recurse-submodules" to switch back
to a branch with the submodule and runs "git submodule update", this
patch is needed to ensure that commands using the submodule directly
are aware of the path to the worktree.

It is late in the release cycle, so revert the whole 3-patch series.
We can try again later for 2.20.

Reported-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/submodule--helper.c

@@ -1123,8 +1123,6 @@ static void deinit_submodule(const char *path, const char *prefix,
 		if (!(flags & OPT_QUIET))
 			printf(format, displaypath);
-		submodule_unset_core_worktree(sub);
-
 		strbuf_release(&sb_rm);
 	}
@@ -2005,29 +2003,6 @@ static int check_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
-static int connect_gitdir_workingtree(int argc, const char **argv, const char *prefix)
-{
-	struct strbuf sb = STRBUF_INIT;
-	const char *name, *path;
-	char *sm_gitdir;
-
-	if (argc != 3)
-		BUG("submodule--helper connect-gitdir-workingtree <name> <path>");
-
-	name = argv[1];
-	path = argv[2];
-
-	strbuf_addf(&sb, "%s/modules/%s", get_git_dir(), name);
-	sm_gitdir = absolute_pathdup(sb.buf);
-
-	connect_work_tree_and_git_dir(path, sm_gitdir, 0);
-
-	strbuf_release(&sb);
-	free(sm_gitdir);
-
-	return 0;
-}
-
 #define SUPPORT_SUPER_PREFIX (1<<0)
 struct cmd_struct {
@@ -2041,7 +2016,6 @@ static struct cmd_struct commands[] = {
 	{"name", module_name, 0},
 	{"clone", module_clone, 0},
 	{"update-clone", update_clone, 0},
-	{"connect-gitdir-workingtree", connect_gitdir_workingtree, 0},
 	{"relative-path", resolve_relative_path, 0},
 	{"resolve-relative-url", resolve_relative_url, 0},
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},

git-submodule.sh

@@ -580,11 +580,6 @@ cmd_update()
 			die "$(eval_gettext "Unable to find current \${remote_name}/\${branch} revision in submodule path '\$sm_path'")"
 		fi
-		if ! $(git config -f "$(git rev-parse --git-common-dir)/modules/$name/config" core.worktree) 2>/dev/null
-		then
-			git submodule--helper connect-gitdir-workingtree "$name" "$sm_path"
-		fi
-
 		if test "$subsha1" != "$sha1" || test -n "$force"
 		then
 			subforce=$force

submodule.c

@@ -1534,18 +1534,6 @@ int bad_to_remove_submodule(const char *path, unsigned flags)
 	return ret;
 }
-void submodule_unset_core_worktree(const struct submodule *sub)
-{
-	char *config_path = xstrfmt("%s/modules/%s/config",
-				    get_git_common_dir(), sub->name);
-
-	if (git_config_set_in_file_gently(config_path, "core.worktree", NULL))
-		warning(_("Could not unset core.worktree setting in submodule '%s'"),
-			  sub->path);
-
-	free(config_path);
-}
-
 static const char *get_super_prefix_or_empty(void)
 {
 	const char *s = get_super_prefix();
@@ -1711,8 +1699,6 @@ int submodule_move_head(const char *path,
 			if (is_empty_dir(path))
 				rmdir_or_warn(path);
-
-			submodule_unset_core_worktree(sub);
 		}
 	}
 out:

submodule.h

@@ -127,8 +127,6 @@ int submodule_move_head(const char *path,
 			const char *new_head,
 			unsigned flags);
-void submodule_unset_core_worktree(const struct submodule *sub);
-
 /*
  * Prepare the "env_array" parameter of a "struct child_process" for executing
  * a submodule by clearing any repo-specific environment variables, but

t/lib-submodule-update.sh

@@ -235,7 +235,7 @@ reset_work_tree_to_interested () {
 	then
 		mkdir -p submodule_update/.git/modules/sub1/modules &&
 		cp -r submodule_update_repo/.git/modules/sub1/modules/sub2 submodule_update/.git/modules/sub1/modules/sub2
-		# core.worktree is unset for sub2 as it is not checked out
+		GIT_WORK_TREE=. git -C submodule_update/.git/modules/sub1/modules/sub2 config --unset core.worktree
 	fi &&
 	# indicate we are interested in the submodule:
 	git -C submodule_update config submodule.sub1.url "bogus" &&
@@ -709,8 +709,7 @@ test_submodule_recursing_with_args_common() {
 			git branch -t remove_sub1 origin/remove_sub1 &&
 			$command remove_sub1 &&
 			test_superproject_content origin/remove_sub1 &&
-			! test -e sub1 &&
-			test_must_fail git config -f .git/modules/sub1/config core.worktree
+			! test -e sub1
 		)
 	'
 	# ... absorbing a .git directory along the way.

t/t7400-submodule-basic.sh

@@ -984,11 +984,6 @@ test_expect_success 'submodule deinit should remove the whole submodule section
 	rmdir init
 '
-test_expect_success 'submodule deinit should unset core.worktree' '
-	test_path_is_file .git/modules/example/config &&
-	test_must_fail git config -f .git/modules/example/config core.worktree
-'
-
 test_expect_success 'submodule deinit from subdirectory' '
 	git submodule update --init &&
 	git config submodule.example.foo bar &&