Merge branch 'gc/branch-recurse-submodules'

"git branch" learned the "--recurse-submodules" option.

* gc/branch-recurse-submodules:
  branch.c: use 'goto cleanup' in setup_tracking() to fix memory leaks
  branch: add --recurse-submodules option for branch creation
  builtin/branch: consolidate action-picking logic in cmd_branch()
  branch: add a dry_run parameter to create_branch()
  branch: make create_branch() always create a branch
  branch: move --set-upstream-to behavior to dwim_and_setup_tracking()

2 files changed, 309 insertions, 0 deletions

diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 1bc3795..7a0ff75 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -42,6 +42,23 @@ test_expect_success 'git branch abc should create a branch' '
 	git branch abc && test_path_is_file .git/refs/heads/abc
 '
 
+test_expect_success 'git branch abc should fail when abc exists' '
+	test_must_fail git branch abc
+'
+
+test_expect_success 'git branch --force abc should fail when abc is checked out' '
+	test_when_finished git switch main &&
+	git switch abc &&
+	test_must_fail git branch --force abc HEAD~1
+'
+
+test_expect_success 'git branch --force abc should succeed when abc exists' '
+	git rev-parse HEAD~1 >expect &&
+	git branch --force abc HEAD~1 &&
+	git rev-parse abc >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'git branch a/b/c should create a branch' '
 	git branch a/b/c && test_path_is_file .git/refs/heads/a/b/c
 '
diff --git a/t/t3207-branch-submodule.sh b/t/t3207-branch-submodule.sh
new file mode 100755
index 0000000..0d93f75
--- /dev/null
+++ b/t/t3207-branch-submodule.sh
@@ -0,0 +1,292 @@
+#!/bin/sh
+
+test_description='git branch submodule tests'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+pwd=$(pwd)
+
+# Creates a clean test environment in "pwd" by copying the repo setup
+# from test_dirs.
+reset_test () {
+	rm -fr super &&
+	rm -fr sub-sub-upstream &&
+	rm -fr sub-upstream &&
+	cp -r test_dirs/* .
+}
+
+# Tests that the expected branch does not exist
+test_no_branch () {
+	DIR=$1 &&
+	BRANCH_NAME=$2 &&
+	test_must_fail git -C "$DIR" rev-parse "$BRANCH_NAME" 2>err &&
+	grep "ambiguous argument .$BRANCH_NAME." err
+}
+
+test_expect_success 'setup superproject and submodule' '
+	mkdir test_dirs &&
+	(
+		cd test_dirs &&
+		git init super &&
+		test_commit -C super foo &&
+		git init sub-sub-upstream &&
+		test_commit -C sub-sub-upstream foo &&
+		git init sub-upstream &&
+		# Submodule in a submodule
+		git -C sub-upstream submodule add "${pwd}/test_dirs/sub-sub-upstream" sub-sub &&
+		git -C sub-upstream commit -m "add submodule" &&
+		# Regular submodule
+		git -C super submodule add "${pwd}/test_dirs/sub-upstream" sub &&
+		# Submodule in a subdirectory
+		git -C super submodule add "${pwd}/test_dirs/sub-sub-upstream" second/sub &&
+		git -C super commit -m "add submodule" &&
+		git -C super config submodule.propagateBranches true &&
+		git -C super/sub submodule update --init
+	) &&
+	reset_test
+'
+
+# Test the argument parsing
+test_expect_success '--recurse-submodules should create branches' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch --recurse-submodules branch-a &&
+		git rev-parse branch-a &&
+		git -C sub rev-parse branch-a &&
+		git -C sub/sub-sub rev-parse branch-a &&
+		git -C second/sub rev-parse branch-a
+	)
+'
+
+test_expect_success '--recurse-submodules should die if submodule.propagateBranches is false' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		echo "fatal: branch with --recurse-submodules can only be used if submodule.propagateBranches is enabled" >expected &&
+		test_must_fail git -c submodule.propagateBranches=false branch --recurse-submodules branch-a 2>actual &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success '--recurse-submodules should fail when not creating branches' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch --recurse-submodules branch-a &&
+		echo "fatal: --recurse-submodules can only be used to create branches" >expected &&
+		test_must_fail git branch --recurse-submodules -D branch-a 2>actual &&
+		test_cmp expected actual &&
+		# Assert that the branches were not deleted
+		git rev-parse branch-a &&
+		git -C sub rev-parse branch-a
+	)
+'
+
+test_expect_success 'should respect submodule.recurse when creating branches' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git -c submodule.recurse=true branch branch-a &&
+		git rev-parse branch-a &&
+		git -C sub rev-parse branch-a
+	)
+'
+
+test_expect_success 'should ignore submodule.recurse when not creating branches' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch --recurse-submodules branch-a &&
+		git -c submodule.recurse=true branch -D branch-a &&
+		test_no_branch . branch-a &&
+		git -C sub rev-parse branch-a
+	)
+'
+
+# Test branch creation behavior
+test_expect_success 'should create branches based off commit id in superproject' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch --recurse-submodules branch-a &&
+		git checkout --recurse-submodules branch-a &&
+		git -C sub rev-parse HEAD >expected &&
+		# Move the tip of sub:branch-a so that it no longer matches the commit in super:branch-a
+		git -C sub checkout branch-a &&
+		test_commit -C sub bar &&
+		# Create a new branch-b branch with start-point=branch-a
+		git branch --recurse-submodules branch-b branch-a &&
+		git rev-parse branch-b &&
+		git -C sub rev-parse branch-b >actual &&
+		# Assert that the commit id of sub:second-branch matches super:branch-a and not sub:branch-a
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'should not create any branches if branch is not valid for all repos' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git -C sub branch branch-a &&
+		test_must_fail git branch --recurse-submodules branch-a 2>actual &&
+		test_no_branch . branch-a &&
+		grep "submodule .sub.: fatal: a branch named .branch-a. already exists" actual
+	)
+'
+
+test_expect_success 'should create branches if branch exists and --force is given' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git -C sub rev-parse HEAD >expected &&
+		test_commit -C sub baz &&
+		# branch-a in sub now points to a newer commit.
+		git -C sub branch branch-a HEAD &&
+		git -C sub rev-parse branch-a >actual-old-branch-a &&
+		git branch --recurse-submodules --force branch-a &&
+		git rev-parse branch-a &&
+		git -C sub rev-parse branch-a >actual-new-branch-a &&
+		test_cmp expected actual-new-branch-a &&
+		# assert that branch --force actually moved the sub
+		# branch
+		! test_cmp expected actual-old-branch-a
+	)
+'
+
+test_expect_success 'should create branch when submodule is not in HEAD:.gitmodules' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch branch-a &&
+		git checkout -b branch-b &&
+		git submodule add ../sub-upstream sub2 &&
+		git -C sub2 submodule update --init &&
+		# branch-b now has a committed submodule not in branch-a
+		git commit -m "add second submodule" &&
+		git checkout branch-a &&
+		git branch --recurse-submodules branch-c branch-b &&
+		git checkout --recurse-submodules branch-c &&
+		git -C sub2 rev-parse branch-c &&
+		git -C sub2/sub-sub rev-parse branch-c
+	)
+'
+
+test_expect_success 'should not create branches in inactive submodules' '
+	test_when_finished "reset_test" &&
+	test_config -C super submodule.sub.active false &&
+	(
+		cd super &&
+		git branch --recurse-submodules branch-a &&
+		git rev-parse branch-a &&
+		test_no_branch sub branch-a
+	)
+'
+
+test_expect_success 'should set up tracking of local branches with track=always' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git -c branch.autoSetupMerge=always branch --recurse-submodules branch-a main &&
+		git -C sub rev-parse main &&
+		test_cmp_config -C sub . branch.branch-a.remote &&
+		test_cmp_config -C sub refs/heads/main branch.branch-a.merge
+	)
+'
+
+test_expect_success 'should set up tracking of local branches with explicit track' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch --track --recurse-submodules branch-a main &&
+		git -C sub rev-parse main &&
+		test_cmp_config -C sub . branch.branch-a.remote &&
+		test_cmp_config -C sub refs/heads/main branch.branch-a.merge
+	)
+'
+
+test_expect_success 'should not set up unnecessary tracking of local branches' '
+	test_when_finished "reset_test" &&
+	(
+		cd super &&
+		git branch --recurse-submodules branch-a main &&
+		git -C sub rev-parse main &&
+		test_cmp_config -C sub "" --default "" branch.branch-a.remote &&
+		test_cmp_config -C sub "" --default "" branch.branch-a.merge
+	)
+'
+
+reset_remote_test () {
+	rm -fr super-clone &&
+	reset_test
+}
+
+test_expect_success 'setup tests with remotes' '
+	(
+		cd test_dirs &&
+		(
+			cd super &&
+			git branch branch-a &&
+			git checkout -b branch-b &&
+			git submodule add ../sub-upstream sub2 &&
+			# branch-b now has a committed submodule not in branch-a
+			git commit -m "add second submodule"
+		) &&
+		git clone --branch main --recurse-submodules super super-clone &&
+		git -C super-clone config submodule.propagateBranches true
+	) &&
+	reset_remote_test
+'
+
+test_expect_success 'should get fatal error upon branch creation when submodule is not in .git/modules' '
+	test_when_finished "reset_remote_test" &&
+	(
+		cd super-clone &&
+		# This should succeed because super-clone has sub in .git/modules
+		git branch --recurse-submodules branch-a origin/branch-a &&
+		# This should fail because super-clone does not have sub2 .git/modules
+		test_must_fail git branch --recurse-submodules branch-b origin/branch-b 2>actual &&
+		grep "fatal: submodule .sub2.: unable to find submodule" actual &&
+		test_no_branch . branch-b &&
+		test_no_branch sub branch-b &&
+		# User can fix themselves by initializing the submodule
+		git checkout origin/branch-b &&
+		git submodule update --init --recursive &&
+		git branch --recurse-submodules branch-b origin/branch-b
+	)
+'
+
+test_expect_success 'should set up tracking of remote-tracking branches' '
+	test_when_finished "reset_remote_test" &&
+	(
+		cd super-clone &&
+		git branch --recurse-submodules branch-a origin/branch-a &&
+		test_cmp_config origin branch.branch-a.remote &&
+		test_cmp_config refs/heads/branch-a branch.branch-a.merge &&
+		# "origin/branch-a" does not exist for "sub", but it matches the refspec
+		# so tracking should be set up
+		test_cmp_config -C sub origin branch.branch-a.remote &&
+		test_cmp_config -C sub refs/heads/branch-a branch.branch-a.merge &&
+		test_cmp_config -C sub/sub-sub origin branch.branch-a.remote &&
+		test_cmp_config -C sub/sub-sub refs/heads/branch-a branch.branch-a.merge
+	)
+'
+
+test_expect_success 'should not fail when unable to set up tracking in submodule' '
+	test_when_finished "reset_remote_test" &&
+	(
+		cd super-clone &&
+		git remote rename origin ex-origin &&
+		git branch --recurse-submodules branch-a ex-origin/branch-a &&
+		test_cmp_config ex-origin branch.branch-a.remote &&
+		test_cmp_config refs/heads/branch-a branch.branch-a.merge &&
+		test_cmp_config -C sub "" --default "" branch.branch-a.remote &&
+		test_cmp_config -C sub "" --default "" branch.branch-a.merge
+	)
+'
+
+test_done