1 files changed, 32 insertions, 0 deletions
diff --git a/testsuite/tests/pmcheck/should_compile/T17112.hs b/testsuite/tests/pmcheck/should_compile/T17112.hs
new file mode 100644
index 0000000000..a6755f71fc
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+++ b/testsuite/tests/pmcheck/should_compile/T17112.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE ViewPatterns #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FunctionalDependencies #-}
+
+import Data.Functor.Identity
+
+data HideArg f where
+  HideArg :: f a -> HideArg f
+
+data family App :: tF -> tF
+data instance App f x = App1 (f x)
+
+class WrappedIn s a | s -> a where
+  unwrap :: s -> a
+
+instance WrappedIn (App f a) (f a) where
+  unwrap (App1 fa) = fa
+
+pattern Unwrapped :: WrappedIn s a => a -> s
+pattern Unwrapped x <- (unwrap -> x)
+{-# COMPLETE Unwrapped :: App #-}
+
+boom :: HideArg (App Identity) -> Bool
+boom (HideArg (Unwrapped (Identity _))) = True
+
+main :: IO ()
+main = print ":("