From: Johannes Schindelin <johannes.schindelin@xxxxxx>
When `remote.<name>.branch` is not configured, `git submodule update`
currently falls back to using the branch name `master`. A much better
idea, however, is to use the remote `HEAD`: on all Git servers running
reasonably recent Git versions, the symref `HEAD` points to the main
branch.
Note: t7419 demonstrates that there _might_ be use cases out there that
_expect_ `git submodule update --remote` to update submodules to the
remote `master` branch even if the remote `HEAD` points to another
branch. Arguably, this patch makes the behavior more intuitive, but
there is a slight possibility that this might cause regressions in
obscure setups.
Even so, it should be okay to fix this behavior without anything like a
longer transition period:
- The `git submodule update --remote` command is not really common.
- Current Git's behavior when running this command is outright
confusing, unless the remote repository's current branch _is_ `master`
(in which case the proposed behavior matches the old behavior).
- If a user encounters a regression due to the changed behavior, the fix
is actually trivial: setting `submodule.<name>.branch` to `master`
will reinstate the old behavior.
Helped-by: Philippe Blain <levraiphilippeblain@xxxxxxxxx>
Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
Documentation/git-submodule.txt | 12 ++++++------
Documentation/gitmodules.txt | 6 +++---
builtin/submodule--helper.c | 2 +-
t/t7406-submodule-update.sh | 16 ++++++++++++++++
t/t7419-submodule-set-branch.sh | 7 +++++--
5 files changed, 31 insertions(+), 12 deletions(-)
diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index c9ed2bf3d5..7e5f995f77 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,7 +183,7 @@ set-branch (-d|--default) [--] <path>::
Sets the default remote tracking branch for the submodule. The
`--branch` option allows the remote branch to be specified. The
`--default` option removes the submodule.<name>.branch configuration
- key, which causes the tracking branch to default to 'master'.
+ key, which causes the tracking branch to default to the remote 'HEAD'.
set-url [--] <path> <newurl>::
Sets the URL of the specified submodule to <newurl>. Then, it will
@@ -284,7 +284,7 @@ OPTIONS
`.gitmodules` for `update --remote`. A special value of `.` is used to
indicate that the name of the branch in the submodule should be the
same name as the current branch in the current repository. If the
- option is not specified, it defaults to 'master'.
+ option is not specified, it defaults to the remote 'HEAD'.
-f::
--force::
@@ -322,10 +322,10 @@ OPTIONS
the superproject's recorded SHA-1 to update the submodule, use the
status of the submodule's remote-tracking branch. The remote used
is branch's remote (`branch.<name>.remote`), defaulting to `origin`.
- The remote branch used defaults to `master`, but the branch name may
- be overridden by setting the `submodule.<name>.branch` option in
- either `.gitmodules` or `.git/config` (with `.git/config` taking
- precedence).
+ The remote branch used defaults to the remote `HEAD`, but the branch
+ name may be overridden by setting the `submodule.<name>.branch`
+ option in either `.gitmodules` or `.git/config` (with `.git/config`
+ taking precedence).
+
This works for any of the supported update procedures (`--checkout`,
`--rebase`, etc.). The only change is the source of the target SHA-1.
diff --git a/Documentation/gitmodules.txt b/Documentation/gitmodules.txt
index 67275fd187..539b4e1997 100644
--- a/Documentation/gitmodules.txt
+++ b/Documentation/gitmodules.txt
@@ -49,9 +49,9 @@ submodule.<name>.update::
submodule.<name>.branch::
A remote branch name for tracking updates in the upstream submodule.
- If the option is not specified, it defaults to 'master'. A special
- value of `.` is used to indicate that the name of the branch in the
- submodule should be the same name as the current branch in the
+ If the option is not specified, it defaults to the remote 'HEAD'.
+ A special value of `.` is used to indicate that the name of the branch
+ in the submodule should be the same name as the current branch in the
current repository. See the `--remote` documentation in
linkgit:git-submodule[1] for details.
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 46c03d2a12..f55f7b7704 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1981,7 +1981,7 @@ static const char *remote_submodule_branch(const char *path)
free(key);
if (!branch)
- return "master";
+ return "HEAD";
if (!strcmp(branch, ".")) {
const char *refname = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index 4fb447a143..aa19ff3a2e 100755
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -70,6 +70,22 @@ test_expect_success 'setup a submodule tree' '
)
'
+test_expect_success 'update --remote falls back to using HEAD' '
+ test_create_repo main-branch-submodule &&
+ test_commit -C main-branch-submodule initial &&
+
+ test_create_repo main-branch &&
+ git -C main-branch submodule add ../main-branch-submodule &&
+ git -C main-branch commit -m add-submodule &&
+
+ git -C main-branch-submodule switch -c hello &&
+ test_commit -C main-branch-submodule world &&
+
+ git clone --recursive main-branch main-branch-clone &&
+ git -C main-branch-clone submodule update --remote main-branch-submodule &&
+ test_path_exists main-branch-clone/main-branch-submodule/world.t
+'
+
test_expect_success 'submodule update detaching the HEAD ' '
(cd super/submodule &&
git reset --hard HEAD~1
diff --git a/t/t7419-submodule-set-branch.sh b/t/t7419-submodule-set-branch.sh
index fd25f786a3..3b925c302f 100755
--- a/t/t7419-submodule-set-branch.sh
+++ b/t/t7419-submodule-set-branch.sh
@@ -52,12 +52,13 @@ test_expect_success 'test submodule set-branch --branch' '
'
test_expect_success 'test submodule set-branch --default' '
+ test_commit -C submodule c &&
(cd super &&
git submodule set-branch --default submodule &&
! grep branch .gitmodules &&
git submodule update --remote &&
cat <<-\EOF >expect &&
- a
+ c
EOF
git -C submodule show -s --pretty=%s >actual &&
test_cmp expect actual
@@ -65,6 +66,7 @@ test_expect_success 'test submodule set-branch --default' '
'
test_expect_success 'test submodule set-branch -b' '
+ test_commit -C submodule b &&
(cd super &&
git submodule set-branch -b topic submodule &&
grep "branch = topic" .gitmodules &&
@@ -78,12 +80,13 @@ test_expect_success 'test submodule set-branch -b' '
'
test_expect_success 'test submodule set-branch -d' '
+ test_commit -C submodule d &&
(cd super &&
git submodule set-branch -d submodule &&
! grep branch .gitmodules &&
git submodule update --remote &&
cat <<-\EOF >expect &&
- a
+ d
EOF
git -C submodule show -s --pretty=%s >actual &&
test_cmp expect actual
--
gitgitgadget
