git rev-parse --verify refs/heads/master
'
+test_expect_success 'merge @{-1}' '
+ git checkout A &&
+ test_commit B &&
+ git checkout A &&
+ test_commit C &&
+ test_commit D &&
+ git branch -f master B &&
+ git branch -f other &&
+ git checkout other &&
+ git checkout master &&
+ git merge @{-1} &&
+ git cat-file commit HEAD | grep "Merge branch '\''other'\''"
+'
+
+test_expect_success 'merge @{-1}~1' '
+ git checkout master &&
+ git reset --hard B &&
+ git checkout other &&
+ git checkout master &&
+ git merge @{-1}~1 &&
+ git cat-file commit HEAD >actual &&
+ grep "Merge branch '\''other'\''" actual
+'
+
+test_expect_success 'merge @{-100} before checking out that many branches yet' '
+ git reflog expire --expire=now &&
+ git checkout -f master &&
+ git reset --hard B &&
+ git branch -f other C &&
+ git checkout other &&
+ git checkout master &&
+ test_must_fail git merge @{-100}
+'
+
test_done