submodule.c: use get_git_dir() instead of get_git_common_dir()

Ever since df56607dff (git-common-dir: make "modules/"
per-working-directory directory, 2014-11-30), submodules in linked worktrees
are cloned to $GIT_DIR/modules, i.e. $GIT_COMMON_DIR/worktrees/<name>/modules.

However, this convention was not followed when the worktree updater commands
checkout, reset and read-tree learned to recurse into submodules. Specifically,
submodule.c::submodule_move_head, introduced in 6e3c1595c6 (update submodules:
add submodule_move_head, 2017-03-14) and submodule.c::submodule_unset_core_worktree,
(re)introduced in 898c2e65b7 (submodule: unset core.worktree if no working tree
is present, 2018-12-14) use get_git_common_dir() instead of get_git_dir()
to get the path of the submodule repository.

This means that, for example, 'git checkout --recurse-submodules <branch>'
in a linked worktree will correctly checkout <branch>, detach the submodule's HEAD
at the commit recorded in <branch> and update the submodule working tree, but the
submodule HEAD that will be moved is the one in $GIT_COMMON_DIR/modules/<name>/,
i.e. the submodule repository of the main superproject working tree.
It will also rewrite the gitfile in the submodule working tree of the linked worktree
to point to $GIT_COMMON_DIR/modules/<name>/.
This leads to an incorrect (and confusing!) state in the submodule working tree
of the main superproject worktree.

Additionally, if switching to a commit where the submodule is not present,
submodule_unset_core_worktree will be called and will incorrectly remove
'core.wortree' from the config file of the submodule in the main superproject worktree,
$GIT_COMMON_DIR/modules/<name>/config.

Fix this by constructing the path to the submodule repository using get_git_dir()
in both submodule_move_head and submodule_unset_core_worktree.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/submodule.c b/submodule.c
index 9da7181321f089e8450ec7e39692f7928f5638a8..5d19ec48a612e35933c504976bfc5c5fcb64b5cd 100644 (file)
--- a/submodule.c
+++ b/submodule.c
@@ -1811,7 +1811,7 @@ out:
 void submodule_unset_core_worktree(const struct submodule *sub)
 {
        char *config_path = xstrfmt("%s/modules/%s/config",
-                                   get_git_common_dir(), sub->name);
+                                   get_git_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'"),
@@ -1914,7 +1914,7 @@ int submodule_move_head(const char *path,
                                        ABSORB_GITDIR_RECURSE_SUBMODULES);
                } else {
                        char *gitdir = xstrfmt("%s/modules/%s",
-                                   get_git_common_dir(), sub->name);
+                                   get_git_dir(), sub->name);
                        connect_work_tree_and_git_dir(path, gitdir, 0);
                        free(gitdir);
 
@@ -1924,7 +1924,7 @@ int submodule_move_head(const char *path,
 
                if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
                        char *gitdir = xstrfmt("%s/modules/%s",
-                                   get_git_common_dir(), sub->name);
+                                   get_git_dir(), sub->name);
                        connect_work_tree_and_git_dir(path, gitdir, 1);
                        free(gitdir);
                }

diff --git a/t/t2405-worktree-submodule.sh b/t/t2405-worktree-submodule.sh
index d0830058fd95b8a478b56a570e7760d418996dab..e1b2bfd87e0d598139ad974db4d546d6d01397b2 100755 (executable)
--- a/t/t2405-worktree-submodule.sh
+++ b/t/t2405-worktree-submodule.sh
@@ -10,6 +10,7 @@ test_expect_success 'setup: create origin repos'  '
        git init origin/sub &&
        test_commit -C origin/sub file1 &&
        git init origin/main &&
+       test_commit -C origin/main first &&
        git -C origin/main submodule add ../sub &&
        git -C origin/main commit -m "add sub" &&
        test_commit -C origin/sub "file1 updated" file1 file1updated file1updated &&
@@ -54,4 +55,36 @@ test_expect_success 'submodule is checked out after manually adding submodule wo
        grep "file1 updated" out
 '
 
+test_expect_success 'checkout --recurse-submodules uses $GIT_DIR for submodules in a linked worktree' '
+       git -C main worktree add "$base_path/checkout-recurse" --detach  &&
+       git -C checkout-recurse submodule update --init &&
+       echo "gitdir: ../../main/.git/worktrees/checkout-recurse/modules/sub" >expect-gitfile &&
+       cat checkout-recurse/sub/.git >actual-gitfile &&
+       test_cmp expect-gitfile actual-gitfile &&
+       git -C main/sub rev-parse HEAD >expect-head-main &&
+       git -C checkout-recurse checkout --recurse-submodules HEAD~1 &&
+       cat checkout-recurse/sub/.git >actual-gitfile &&
+       git -C main/sub rev-parse HEAD >actual-head-main &&
+       test_cmp expect-gitfile actual-gitfile &&
+       test_cmp expect-head-main actual-head-main
+'
+
+test_expect_success 'core.worktree is removed in $GIT_DIR/modules/<name>/config, not in $GIT_COMMON_DIR/modules/<name>/config' '
+       echo "../../../sub" >expect-main &&
+       git -C main/sub config --get core.worktree >actual-main &&
+       test_cmp expect-main actual-main &&
+       echo "../../../../../../checkout-recurse/sub" >expect-linked &&
+       git -C checkout-recurse/sub config --get core.worktree >actual-linked &&
+       test_cmp expect-linked actual-linked &&
+       git -C checkout-recurse checkout --recurse-submodules first &&
+       test_expect_code 1 git -C main/.git/worktrees/checkout-recurse/modules/sub config --get core.worktree >linked-config &&
+       test_must_be_empty linked-config &&
+       git -C main/sub config --get core.worktree >actual-main &&
+       test_cmp expect-main actual-main
+'
+
+test_expect_success 'unsetting core.worktree does not prevent running commands directly against the submodule repository' '
+       git -C main/.git/worktrees/checkout-recurse/modules/sub log
+'
+
 test_done