[PATCH 1/3] add tests for checkout -b

@@ -0,0 +1,66 @@
+#!/bin/sh
+
+test_description='checkout '
+
+. ./test-lib.sh
+
+# Arguments: <branch> <sha> [<checkout options>]
+do_checkout() {
+	exp_branch=$1 &&
+	exp_ref="refs/heads/$exp_branch" &&
+
+	# if <sha> is not specified, use HEAD.
+	exp_sha=${2:-$(git rev-parse --verify HEAD)} &&
+
+	git checkout ${3+"$3"} -b $exp_branch $exp_sha &&
+
+	test $exp_ref = $(git rev-parse --symbolic-full-name HEAD) &&
+	test $exp_sha = $(git rev-parse --verify HEAD)
+}
+
+test_dirty() {
+	! git diff --exit-code >/dev/null
+}
+
+setup_dirty() {
+	echo >>file1 change2
+}
+
+test_expect_success 'setup' '
+	test_commit initial file1 &&
+	HEAD1=$(git rev-parse --verify HEAD) &&
+
+	test_commit change1 file1 &&
+	HEAD2=$(git rev-parse --verify HEAD) &&
+
+	git branch -m branch1
+'
+
+test_expect_success 'checkout -b to a new branch' '
+	do_checkout branch2
+'
+
+test_expect_success 'checkout -b to a new branch (explicit ref)' '
+	git checkout branch1 &&
+	git branch -D branch2 &&
+
+	do_checkout branch2 $HEAD1
+'
+
+test_expect_success 'checkout -b to a new branch (dirty)' '
+	git checkout branch1 &&
+	git branch -D branch2 &&
+
+	setup_dirty &&
+	test_must_fail do_checkout branch2 $HEAD1 &&
+	test_dirty
+'
+
+test_expect_success 'checkout -b to an existing branch fails' '
+	git reset --hard HEAD &&
+	git branch branch2 &&
+
+	test_must_fail do_checkout branch2 $HEAD2
+'
+
+test_done