1 files changed, 40 insertions, 0 deletions
diff --git a/testsuite/tests/printer/T14289c.hs b/testsuite/tests/printer/T14289c.hs
new file mode 100644
index 0000000000..6e58df1a54
--- /dev/null
+++ b/testsuite/tests/printer/T14289c.hs
@@ -0,0 +1,40 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TypeOperators #-}
+{-# OPTIONS_GHC -ddump-splices -dsuppress-uniques #-}
+
+import Language.Haskell.TH
+
+$([d| data Foo a = Foo a deriving (a ~ a) |])
+
+{-
+
+Note: to debug
+
+~/inplace/bin/ghc-stage2 --interactive
+load the following
+----------------------------------------
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# OPTIONS_GHC -ddump-splices -dsuppress-uniques #-}
+
+import Language.Haskell.TH
+
+class (a `C` b) c
+
+main :: IO ()
+main
+  = putStrLn $([d| data Foo a = Foo a deriving (a ~ a) |] >>= stringE . show)
+
+----------------------------------------
+Becomes
+
+[DataD [] Foo_0 [PlainTV a_2] Nothing
+  [NormalC Foo_1 [(Bang NoSourceUnpackedness NoSourceStrictness,VarT a_2)]]
+  [DerivClause Nothing
+    [AppT (AppT EqualityT (VarT a_2))
+          (VarT a_2)]]]
+
+
+-}