Test Trac #12925

testsuite/tests/typecheck/should_compile/T12925.hs

+module Bug where
+
+data Foo a x = Foo x
+
+refoo :: Foo a x -> Foo b x
+{-# NOINLINE refoo #-}
+refoo (Foo x) = Foo x
+
+{-# RULES
+
+"refoo/refoo" forall s.
+  refoo (refoo s) = s  #-}

testsuite/tests/typecheck/should_compile/all.T

@@ -555,4 +555,4 @@ test('T12734', normal, compile, [''])
 test('T12734a', normal, compile_fail, [''])
 test('T12763', normal, compile, [''])
 test('T12797', normal, compile, [''])
-
+test('T12925', normal, compile, [''])