From: Chris Hanson <org/chris-hanson/cph>
Date: Tue, 9 Jan 2007 06:37:50 +0000 (+0000)
Subject: Don't allow MAKE-CONDITIONAL to accept two arguments; require three.
X-Git-Tag: 20090517-FFI~805
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=cfd10af222c9f734b5e170f22fcd3d47aa416da6;p=mit-scheme.git

Don't allow MAKE-CONDITIONAL to accept two arguments; require three.
Otherwise, programs of the form (IF <a> <b> #!DEFAULT) miscompile.
---

diff --git a/v7/src/runtime/scomb.scm b/v7/src/runtime/scomb.scm
index 275b7a977..87188c214 100644
--- a/v7/src/runtime/scomb.scm
+++ b/v7/src/runtime/scomb.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: scomb.scm,v 14.26 2007/01/05 21:19:28 cph Exp $
+$Id: scomb.scm,v 14.27 2007/01/09 06:37:50 cph Exp $
 
 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
     1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
@@ -173,20 +173,16 @@ USA.
 
 ;;;; Conditional
 
-(define (make-conditional predicate consequent #!optional alternative)
-  (let ((alternative
-	 (if (default-object? alternative)
-	     undefined-conditional-branch
-	     alternative)))
-    (if (and (combination? predicate)
-	     (eq? (combination-operator predicate) (ucode-primitive not)))
-	(make-conditional (car (combination-operands predicate))
-			  alternative
-			  consequent)
-	(&typed-triple-cons (ucode-type conditional)
-			    predicate
-			    consequent
-			    alternative))))
+(define (make-conditional predicate consequent alternative)
+  (if (and (combination? predicate)
+	   (eq? (combination-operator predicate) (ucode-primitive not)))
+      (make-conditional (car (combination-operands predicate))
+			alternative
+			consequent)
+      (&typed-triple-cons (ucode-type conditional)
+			  predicate
+			  consequent
+			  alternative)))
 
 (define (conditional? object)
   (object-type? (ucode-type conditional) object))