From f2d6cac2d9eb68f5429fc0bae3056fbcda4f71dc Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <campbell@mumble.net>
Date: Mon, 21 Dec 2009 15:11:16 -0500
Subject: [PATCH] Reflect specification bug in definition of
 HASH-TABLE-UPDATE!.

We can't use HASH-TABLE/MODIFY! because the specification tacitly
permits the procedure to edit the hash table.  This was a silly
oversight in the SRFI document.
---
 src/runtime/hashtb.scm | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/src/runtime/hashtb.scm b/src/runtime/hashtb.scm
index a0fa9274c..e5fe7f896 100644
--- a/src/runtime/hashtb.scm
+++ b/src/runtime/hashtb.scm
@@ -840,19 +840,16 @@ USA.
 	datum)))
 
 (define (hash-table-update! table key procedure #!optional get-default)
-  (hash-table/modify! table
-		      key
-		      (if (default-object? get-default)
-			  (lambda (datum)
-			    (if (eq? datum default-marker)
-				(error:bad-range-argument key
-							  'HASH-TABLE-UPDATE!))
-			    (procedure datum))
-			  (lambda (datum)
-			    (procedure (if (eq? datum default-marker)
-					   (get-default)
-					   datum))))
-		      default-marker))
+  (hash-table-set!
+   table
+   key
+   (procedure
+    (hash-table-ref table
+		    key
+		    (if (default-object? get-default)
+			(lambda ()
+			  (error:bad-range-argument key 'HASH-TABLE-UPDATE!))
+			get-default)))))
 
 (define (hash-table-copy table)
   (guarantee-hash-table table 'HASH-TABLE-COPY)
-- 
2.25.1