1 files changed, 336 insertions, 0 deletions
diff --git a/third_party/git/t/t2024-checkout-dwim.sh b/third_party/git/t/t2024-checkout-dwim.sh
new file mode 100755
index 0000000000..accfa9aa4b
--- /dev/null
+++ b/third_party/git/t/t2024-checkout-dwim.sh
@@ -0,0 +1,336 @@
+#!/bin/sh
+
+test_description='checkout <branch>
+
+Ensures that checkout on an unborn branch does what the user expects'
+
+. ./test-lib.sh
+
+# Is the current branch "refs/heads/$1"?
+test_branch () {
+	printf "%s\n" "refs/heads/$1" >expect.HEAD &&
+	git symbolic-ref HEAD >actual.HEAD &&
+	test_cmp expect.HEAD actual.HEAD
+}
+
+# Is branch "refs/heads/$1" set to pull from "$2/$3"?
+test_branch_upstream () {
+	printf "%s\n" "$2" "refs/heads/$3" >expect.upstream &&
+	{
+		git config "branch.$1.remote" &&
+		git config "branch.$1.merge"
+	} >actual.upstream &&
+	test_cmp expect.upstream actual.upstream
+}
+
+status_uno_is_clean () {
+	git status -uno --porcelain >status.actual &&
+	test_must_be_empty status.actual
+}
+
+test_expect_success 'setup' '
+	test_commit my_master &&
+	git init repo_a &&
+	(
+		cd repo_a &&
+		test_commit a_master &&
+		git checkout -b foo &&
+		test_commit a_foo &&
+		git checkout -b bar &&
+		test_commit a_bar &&
+		git checkout -b ambiguous_branch_and_file &&
+		test_commit a_ambiguous_branch_and_file
+	) &&
+	git init repo_b &&
+	(
+		cd repo_b &&
+		test_commit b_master &&
+		git checkout -b foo &&
+		test_commit b_foo &&
+		git checkout -b baz &&
+		test_commit b_baz &&
+		git checkout -b ambiguous_branch_and_file &&
+		test_commit b_ambiguous_branch_and_file
+	) &&
+	git remote add repo_a repo_a &&
+	git remote add repo_b repo_b &&
+	git config remote.repo_b.fetch \
+		"+refs/heads/*:refs/remotes/other_b/*" &&
+	git fetch --all
+'
+
+test_expect_success 'checkout of non-existing branch fails' '
+	git checkout -B master &&
+	test_might_fail git branch -D xyzzy &&
+
+	test_must_fail git checkout xyzzy &&
+	status_uno_is_clean &&
+	test_must_fail git rev-parse --verify refs/heads/xyzzy &&
+	test_branch master
+'
+
+test_expect_success 'checkout of branch from multiple remotes fails #1' '
+	git checkout -B master &&
+	test_might_fail git branch -D foo &&
+
+	test_must_fail git checkout foo &&
+	status_uno_is_clean &&
+	test_must_fail git rev-parse --verify refs/heads/foo &&
+	test_branch master
+'
+
+test_expect_success 'when arg matches multiple remotes, do not fallback to interpreting as pathspec' '
+	# create a file with name matching remote branch name
+	git checkout -b t_ambiguous_branch_and_file &&
+	>ambiguous_branch_and_file &&
+	git add ambiguous_branch_and_file &&
+	git commit -m "ambiguous_branch_and_file" &&
+
+	# modify file to verify that it will not be touched by checkout
+	test_when_finished "git checkout -- ambiguous_branch_and_file" &&
+	echo "file contents" >ambiguous_branch_and_file &&
+	cp ambiguous_branch_and_file expect &&
+
+	test_must_fail git checkout ambiguous_branch_and_file 2>err &&
+
+	test_i18ngrep "matched multiple (2) remote tracking branches" err &&
+
+	# file must not be altered
+	test_cmp expect ambiguous_branch_and_file
+'
+
+test_expect_success 'checkout of branch from multiple remotes fails with advice' '
+	git checkout -B master &&
+	test_might_fail git branch -D foo &&
+	test_must_fail git checkout foo 2>stderr &&
+	test_branch master &&
+	status_uno_is_clean &&
+	test_i18ngrep "^hint: " stderr &&
+	test_must_fail git -c advice.checkoutAmbiguousRemoteBranchName=false \
+		checkout foo 2>stderr &&
+	test_branch master &&
+	status_uno_is_clean &&
+	test_i18ngrep ! "^hint: " stderr
+'
+
+test_expect_success PERL 'checkout -p with multiple remotes does not print advice' '
+	git checkout -B master &&
+	test_might_fail git branch -D foo &&
+
+	git checkout -p foo 2>stderr &&
+	test_i18ngrep ! "^hint: " stderr &&
+	status_uno_is_clean
+'
+
+test_expect_success 'checkout of branch from multiple remotes succeeds with checkout.defaultRemote #1' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D foo &&
+
+	git -c checkout.defaultRemote=repo_a checkout foo &&
+	status_uno_is_clean &&
+	test_branch foo &&
+	test_cmp_rev remotes/repo_a/foo HEAD &&
+	test_branch_upstream foo repo_a foo
+'
+
+test_expect_success 'checkout of branch from a single remote succeeds #1' '
+	git checkout -B master &&
+	test_might_fail git branch -D bar &&
+
+	git checkout bar &&
+	status_uno_is_clean &&
+	test_branch bar &&
+	test_cmp_rev remotes/repo_a/bar HEAD &&
+	test_branch_upstream bar repo_a bar
+'
+
+test_expect_success 'checkout of branch from a single remote succeeds #2' '
+	git checkout -B master &&
+	test_might_fail git branch -D baz &&
+
+	git checkout baz &&
+	status_uno_is_clean &&
+	test_branch baz &&
+	test_cmp_rev remotes/other_b/baz HEAD &&
+	test_branch_upstream baz repo_b baz
+'
+
+test_expect_success '--no-guess suppresses branch auto-vivification' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D bar &&
+
+	test_must_fail git checkout --no-guess bar &&
+	test_must_fail git rev-parse --verify refs/heads/bar &&
+	test_branch master
+'
+
+test_expect_success 'setup more remotes with unconventional refspecs' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	git init repo_c &&
+	(
+		cd repo_c &&
+		test_commit c_master &&
+		git checkout -b bar &&
+		test_commit c_bar &&
+		git checkout -b spam &&
+		test_commit c_spam
+	) &&
+	git init repo_d &&
+	(
+		cd repo_d &&
+		test_commit d_master &&
+		git checkout -b baz &&
+		test_commit d_baz &&
+		git checkout -b eggs &&
+		test_commit d_eggs
+	) &&
+	git remote add repo_c repo_c &&
+	git config remote.repo_c.fetch \
+		"+refs/heads/*:refs/remotes/extra_dir/repo_c/extra_dir/*" &&
+	git remote add repo_d repo_d &&
+	git config remote.repo_d.fetch \
+		"+refs/heads/*:refs/repo_d/*" &&
+	git fetch --all
+'
+
+test_expect_success 'checkout of branch from multiple remotes fails #2' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D bar &&
+
+	test_must_fail git checkout bar &&
+	status_uno_is_clean &&
+	test_must_fail git rev-parse --verify refs/heads/bar &&
+	test_branch master
+'
+
+test_expect_success 'checkout of branch from multiple remotes fails #3' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D baz &&
+
+	test_must_fail git checkout baz &&
+	status_uno_is_clean &&
+	test_must_fail git rev-parse --verify refs/heads/baz &&
+	test_branch master
+'
+
+test_expect_success 'checkout of branch from a single remote succeeds #3' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D spam &&
+
+	git checkout spam &&
+	status_uno_is_clean &&
+	test_branch spam &&
+	test_cmp_rev refs/remotes/extra_dir/repo_c/extra_dir/spam HEAD &&
+	test_branch_upstream spam repo_c spam
+'
+
+test_expect_success 'checkout of branch from a single remote succeeds #4' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D eggs &&
+
+	git checkout eggs &&
+	status_uno_is_clean &&
+	test_branch eggs &&
+	test_cmp_rev refs/repo_d/eggs HEAD &&
+	test_branch_upstream eggs repo_d eggs
+'
+
+test_expect_success 'checkout of branch with a file having the same name fails' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D spam &&
+
+	>spam &&
+	test_must_fail git checkout spam &&
+	status_uno_is_clean &&
+	test_must_fail git rev-parse --verify refs/heads/spam &&
+	test_branch master
+'
+
+test_expect_success 'checkout of branch with a file in subdir having the same name fails' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D spam &&
+
+	>spam &&
+	mkdir sub &&
+	mv spam sub/spam &&
+	test_must_fail git -C sub checkout spam &&
+	status_uno_is_clean &&
+	test_must_fail git rev-parse --verify refs/heads/spam &&
+	test_branch master
+'
+
+test_expect_success 'checkout <branch> -- succeeds, even if a file with the same name exists' '
+	git checkout -B master &&
+	status_uno_is_clean &&
+	test_might_fail git branch -D spam &&
+
+	>spam &&
+	git checkout spam -- &&
+	status_uno_is_clean &&
+	test_branch spam &&
+	test_cmp_rev refs/remotes/extra_dir/repo_c/extra_dir/spam HEAD &&
+	test_branch_upstream spam repo_c spam
+'
+
+test_expect_success 'loosely defined local base branch is reported correctly' '
+
+	git checkout master &&
+	status_uno_is_clean &&
+	git branch strict &&
+	git branch loose &&
+	git commit --allow-empty -m "a bit more" &&
+
+	test_config branch.strict.remote . &&
+	test_config branch.loose.remote . &&
+	test_config branch.strict.merge refs/heads/master &&
+	test_config branch.loose.merge master &&
+
+	git checkout strict | sed -e "s/strict/BRANCHNAME/g" >expect &&
+	status_uno_is_clean &&
+	git checkout loose | sed -e "s/loose/BRANCHNAME/g" >actual &&
+	status_uno_is_clean &&
+
+	test_cmp expect actual
+'
+
+test_expect_success 'reject when arg could be part of dwim branch' '
+	git remote add foo file://non-existent-place &&
+	git update-ref refs/remotes/foo/dwim-arg HEAD &&
+	echo foo >dwim-arg &&
+	git add dwim-arg &&
+	echo bar >dwim-arg &&
+	test_must_fail git checkout dwim-arg &&
+	test_must_fail git rev-parse refs/heads/dwim-arg -- &&
+	grep bar dwim-arg
+'
+
+test_expect_success 'disambiguate dwim branch and checkout path (1)' '
+	git update-ref refs/remotes/foo/dwim-arg1 HEAD &&
+	echo foo >dwim-arg1 &&
+	git add dwim-arg1 &&
+	echo bar >dwim-arg1 &&
+	git checkout -- dwim-arg1 &&
+	test_must_fail git rev-parse refs/heads/dwim-arg1 -- &&
+	grep foo dwim-arg1
+'
+
+test_expect_success 'disambiguate dwim branch and checkout path (2)' '
+	git update-ref refs/remotes/foo/dwim-arg2 HEAD &&
+	echo foo >dwim-arg2 &&
+	git add dwim-arg2 &&
+	echo bar >dwim-arg2 &&
+	git checkout dwim-arg2 -- &&
+	git rev-parse refs/heads/dwim-arg2 -- &&
+	grep bar dwim-arg2
+'
+
+test_done