Merge branch 'ci/forbid-unwanted-current-branch-update'

* ci/forbid-unwanted-current-branch-update:
  Show interpreted branch name in error messages
  Prevent force-updating of the current branch

2 files changed, 29 insertions, 0 deletions

diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
index a42e03967..75874e85d 100755
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -118,6 +118,15 @@ test_expect_success 'checkout -b to an existing branch fails' '
 	test_must_fail do_checkout branch2 $HEAD2
 '
 
+test_expect_success 'checkout -b to @{-1} fails with the right branch name' '
+	git reset --hard HEAD &&
+	git checkout branch1 &&
+	git checkout branch2 &&
+	echo  >expect "fatal: A branch named '\''branch1'\'' already exists." &&
+	test_must_fail git checkout -b @{-1} 2>actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'checkout -B to an existing branch resets branch to HEAD' '
 	git checkout branch1 &&
 
@@ -180,4 +189,12 @@ test_expect_success 'checkout -b <describe>' '
 	test_cmp expect actual
 '
 
+test_expect_success 'checkout -B to the current branch fails before merging' '
+	git checkout branch1 &&
+	setup_dirty_mergeable &&
+	git commit -mfooble &&
+	test_must_fail git checkout -B branch1 initial &&
+	test_must_fail test_dirty_mergeable
+'
+
 test_done
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 9e69c8c92..cb6458d1c 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -98,6 +98,18 @@ test_expect_success 'git branch -m q r/q should fail when r exists' '
 	test_must_fail git branch -m q r/q
 '
 
+test_expect_success 'git branch -M foo bar should fail when bar is checked out' '
+	git branch bar &&
+	git checkout -b foo &&
+	test_must_fail git branch -M bar foo
+'
+
+test_expect_success 'git branch -M baz bam should succeed when baz is checked out' '
+	git checkout -b baz &&
+	git branch bam &&
+	git branch -M baz bam
+'
+
 mv .git/config .git/config-saved
 
 test_expect_success 'git branch -m q q2 without config should succeed' '