git tag topic
'
+test_expect_success 'rebase on dirty worktree' '
+ echo dirty >> A &&
+ test_must_fail git rebase master'
+
+test_expect_success 'rebase on dirty cache' '
+ git add A &&
+ test_must_fail git rebase master'
+
test_expect_success 'rebase against master' '
+ git reset --hard HEAD &&
git rebase master'
+test_expect_success 'rebase against master twice' '
+ git rebase master 2>err &&
+ grep "Current branch my-topic-branch is up to date" err
+'
+
+test_expect_success 'rebase against master twice with --force' '
+ git rebase --force-rebase master >out &&
+ grep "Current branch my-topic-branch is up to date, rebase forced" out
+'
+
+test_expect_success 'rebase against master twice from another branch' '
+ git checkout my-topic-branch^ &&
+ git rebase master my-topic-branch 2>err &&
+ grep "Current branch my-topic-branch is up to date" err
+'
+
+test_expect_success 'rebase fast-forward to master' '
+ git checkout my-topic-branch^ &&
+ git rebase my-topic-branch 2>err &&
+ grep "Fast-forwarded HEAD to my-topic-branch" err
+'
+
test_expect_success \
'the rebase operation should not have destroyed author information' \
'! (git log | grep "Author:" | grep "<>")'