Fix Trac #3342: missed zonking in TcHsSyn

The type in a ViewPat wasn't being zonked.  Easily fixed.

diff --git a/compiler/typecheck/TcHsSyn.lhs b/compiler/typecheck/TcHsSyn.lhs
index fa54a63..ffd2893 100644 (file)
--- a/compiler/typecheck/TcHsSyn.lhs
+++ b/compiler/typecheck/TcHsSyn.lhs
@@ -822,7 +822,8 @@ zonk_pat env (AsPat (L loc v) pat)
 zonk_pat env (ViewPat expr pat ty)
   = do { expr' <- zonkLExpr env expr
        ; (env', pat') <- zonkPat env pat
-       ; return (env', ViewPat expr' pat' ty) }
+       ; ty' <- zonkTcTypeToType env ty
+       ; return (env', ViewPat expr' pat' ty') }
 
 zonk_pat env (ListPat pats ty)
   = do { ty' <- zonkTcTypeToType env ty