@matheusbsbs / matheus-bagliano / commits / f0a96e8d4c

submodule: fall back to remote's HEAD for missing remote.<name>.branch

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@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Jun 24, 2020 at 14:46 UTC f0a96e8d4c98c2394dc726b57b914f95cbc7a0de

5 files changed +31 -12

Documentation/git-submodule.txt

+6 -6

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.

Documentation/gitmodules.txt

+3 -3

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.

builtin/submodule--helper.c

+1 -1

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);

t/t7406-submodule-update.sh

+16

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

t/t7419-submodule-set-branch.sh

+5 -2

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