From 1551823b9461f62755a30086ea18c7149b09b2bc Mon Sep 17 00:00:00 2001
From: simonpj <unknown>
Date: Tue, 26 Mar 2002 19:08:19 +0000
Subject: [PATCH] [project @ 2002-03-26 19:08:19 by simonpj] Fix
 readHoleResult bug

---
 ghc/compiler/typecheck/TcPat.lhs |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/ghc/compiler/typecheck/TcPat.lhs b/ghc/compiler/typecheck/TcPat.lhs
index cb08317..ea64699 100644
--- a/ghc/compiler/typecheck/TcPat.lhs
+++ b/ghc/compiler/typecheck/TcPat.lhs
@@ -139,7 +139,10 @@ tcPat tc_bndr pat_in@(AsPatIn name pat) pat_ty
 	      tvs, (name, bndr_id) `consBag` ids, lie_avail)
 
 tcPat tc_bndr WildPatIn pat_ty
-  = returnTc (WildPat pat_ty, emptyLIE, emptyBag, emptyBag, emptyLIE)
+  = zapToType pat_ty			`thenNF_Tc` \ pat_ty' ->
+	-- We might have an incoming 'hole' type variable; no annotation
+	-- so zap it to a type.  Rather like tcMonoPatBndr.
+    returnTc (WildPat pat_ty', emptyLIE, emptyBag, emptyBag, emptyLIE)
 
 tcPat tc_bndr (ParPatIn parend_pat) pat_ty
   = tcPat tc_bndr parend_pat pat_ty
-- 
1.7.10.4