X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FDataCon.lhs;h=dbc63552045b56f1d8182c09ea49bcc4e16bfa11;hb=af2db474c2bb80e29924430e3c730bc217e55189;hp=9ce966ee7743dbbfff37e6288f352bd5f5d10374;hpb=00b6d2567426ec52a113b1d3687e1d61368cafda;p=ghc-hetmet.git

diff --git a/compiler/basicTypes/DataCon.lhs b/compiler/basicTypes/DataCon.lhs
index 9ce966e..dbc6355 100644
--- a/compiler/basicTypes/DataCon.lhs
+++ b/compiler/basicTypes/DataCon.lhs
@@ -766,8 +766,9 @@ splitProductType str ty
 deepSplitProductType_maybe ty
   = do { (res@(tycon, tycon_args, _, _)) <- splitProductType_maybe ty
        ; let {result 
-             | isClosedNewTyCon tycon && not (isRecursiveTyCon tycon)
-             = deepSplitProductType_maybe (newTyConInstRhs tycon tycon_args)
+             | Just (ty', _co) <- instNewTyCon_maybe tycon tycon_args
+	     , not (isRecursiveTyCon tycon)
+             = deepSplitProductType_maybe ty'	-- Ignore the coercion?
              | isNewTyCon tycon = Nothing  -- cannot unbox through recursive
 					   -- newtypes nor through families
              | otherwise = Just res}