From: simonpj@microsoft.com <unknown>
Date: Fri, 8 Oct 2010 11:13:18 +0000 (+0000)
Subject: Suppress ambiguity errors if any other errors occur
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=7e3ec3f3aa3ecaf39cb4519f562ee20debcb5ece

Suppress ambiguity errors if any other errors occur
---

diff --git a/compiler/typecheck/TcErrors.lhs b/compiler/typecheck/TcErrors.lhs
index 0ade93c..1254dd6 100644
--- a/compiler/typecheck/TcErrors.lhs
+++ b/compiler/typecheck/TcErrors.lhs
@@ -125,10 +125,9 @@ reportTidyWanteds ctxt unsolved
        ; when (null tv_eqs) $ groupErrs (reportFlat ctxt) others
        ; when (null tv_eqs) $ mapBagM_ (reportTidyImplic ctxt) implics
 
-       	   -- Only report ambiguity if no other errors happened
-	   -- See Note [Avoiding spurious errors]
-       ; when (isEmptyBag implics && null non_ambigs) $
-         reportAmbigErrs ctxt skols ambigs }
+       	   -- Only report ambiguity if no other errors (at all) happened
+	   -- See Note [Avoiding spurious errors] in TcSimplify
+       ; ifErrsM (return ()) $ reportAmbigErrs ctxt skols ambigs }
   where
     skols = foldr (unionVarSet . ic_skols) emptyVarSet (cec_encl ctxt)