X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDsBinds.lhs;h=5be1774c31d3d269c27a3b9582fe277536ffd4a2;hb=03aa4b6dfb67cc20b94b5fb19c8e8c5958603ea6;hp=87fda8eb18e298330e41acffcf226b7e8163f070;hpb=9d836b9c4887e861c8f39a41d7bdab23d9d1d803;p=ghc-hetmet.git

diff --git a/ghc/compiler/deSugar/DsBinds.lhs b/ghc/compiler/deSugar/DsBinds.lhs
index 87fda8e..5be1774 100644
--- a/ghc/compiler/deSugar/DsBinds.lhs
+++ b/ghc/compiler/deSugar/DsBinds.lhs
@@ -266,11 +266,13 @@ decomposeRuleLhs all_bndrs lhs
 
 	-- Substitute dicts in the LHS args, so that there 
 	-- aren't any lets getting in the way
+	-- Note that we substitute the function too; we might have this as
+	-- a LHS:	let f71 = M.f Int in f71
     go env (Let (NonRec dict rhs) body) 
 	= go (extendVarEnv env dict (simpleSubst env rhs)) body
     go env body 
-	= case collectArgs body of
-	    (Var fn, args) -> Just (all_bndrs', fn, map (simpleSubst env) args)
+	= case collectArgs (simpleSubst env body) of
+	    (Var fn, args) -> Just (all_bndrs', fn, args)
 	    other 	   -> Nothing
 
 simpleSubst :: IdEnv CoreExpr -> CoreExpr -> CoreExpr