From b1c3d11ac8c6841fa785e016cb602a1ea4aa7705 Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Thu, 6 Dec 2001 14:42:56 +0000
Subject: [PATCH] [project @ 2001-12-06 14:42:56 by simonmar] Turn a lazy
 pattern match into a strict one in tidyIdBndr.  This
 prevents us accidentally hanging onto stuff in the OccName
 field of a Name after tidying.

---
 ghc/compiler/coreSyn/CoreTidy.lhs |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/ghc/compiler/coreSyn/CoreTidy.lhs b/ghc/compiler/coreSyn/CoreTidy.lhs
index 344a5db..f8842b9 100644
--- a/ghc/compiler/coreSyn/CoreTidy.lhs
+++ b/ghc/compiler/coreSyn/CoreTidy.lhs
@@ -670,9 +670,12 @@ tidyLetBndr env (id,rhs)
     -- so it gets propagated to the usage sites.
     new_var_env = extendVarEnv var_env id final_id
 
+-- Non-top-level variables
 tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
 tidyIdBndr env@(tidy_env, var_env) id
-  = 	-- Non-top-level variables
+  = -- do this pattern match strictly, otherwise we end up holding on to
+    -- stuff in the OccName.
+    case tidyOccName tidy_env (getOccName id) of { (tidy_env', occ') -> 
     let 
 	-- Give the Id a fresh print-name, *and* rename its type
 	-- The SrcLoc isn't important now, 
@@ -680,12 +683,12 @@ tidyIdBndr env@(tidy_env, var_env) id
 	-- 
 	-- All nested Ids now have the same IdInfo, namely none,
 	-- which should save some space.
-	(tidy_env', occ') = tidyOccName tidy_env (getOccName id)
         ty'          	  = tidyType env (idType id)
 	id'          	  = mkUserLocal occ' (idUnique id) ty' noSrcLoc
 	var_env'	  = extendVarEnv var_env id id'
     in
      ((tidy_env', var_env'), id')
+   }
 \end{code}
 
 \begin{code}
-- 
1.7.10.4