From 45e446f05efa8525f860f2292027068ed53dc23d Mon Sep 17 00:00:00 2001
From: sewardj <unknown>
Date: Wed, 1 Dec 1999 12:02:48 +0000
Subject: [PATCH] [project @ 1999-12-01 12:02:48 by sewardj] Disable the Mark
 Jones optimisation for instance decls, since it is
 incompatible with Hugs.

---
 ghc/compiler/basicTypes/MkId.lhs |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/ghc/compiler/basicTypes/MkId.lhs b/ghc/compiler/basicTypes/MkId.lhs
index 158cc3d..878868f 100644
--- a/ghc/compiler/basicTypes/MkId.lhs
+++ b/ghc/compiler/basicTypes/MkId.lhs
@@ -453,6 +453,11 @@ mkDictFunId dfun_name clas inst_tyvars inst_tys inst_decl_theta
     (class_tyvars, sc_theta, _, _) = classBigSig clas
     sc_theta' = substTheta (mkTopTyVarSubst class_tyvars inst_tys) sc_theta
 
+    dfun_theta = inst_decl_theta
+
+{-  1 dec 99: disable the Mark Jones optimisation for the sake
+    of compatibility with Hugs.
+
     dfun_theta = case inst_decl_theta of
 		   []    -> []	-- If inst_decl_theta is empty, then we don't
 				-- want to have any dict arguments, so that we can
@@ -472,7 +477,7 @@ mkDictFunId dfun_name clas inst_tyvars inst_tys inst_decl_theta
 				--   class Foo a => Baz a b where ...
 				--   instance Wob b => Baz T b where..
 				-- Now sc_theta' has Foo T
-
+-}
     dfun_ty = mkSigmaTy inst_tyvars dfun_theta (mkDictTy clas inst_tys)
 
     not_const (clas, tys) = not (isEmptyVarSet (tyVarsOfTypes tys))
-- 
1.7.10.4