diff --git a/tests/test-rename.out b/tests/test-rename.out
--- a/tests/test-rename.out
+++ b/tests/test-rename.out
@@ -252,3 +252,5 @@ R d1/b
 # transitive rename --after
 A d1/bc
 R d1/b
+# idempotent renames (d1/b -> d1/bb followed by d1/bb -> d1/b)
+M d1/b