From: Chris Hanson <org/chris-hanson/cph>
Date: Sun, 15 Apr 2007 17:43:08 +0000 (+0000)
Subject: Tweak.
X-Git-Tag: 20090517-FFI~644
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=bb56f6b65548c785b85ea074de4786f80fdcfca5;p=mit-scheme.git

Tweak.
---

diff --git a/v7/src/runtime/unxpth.scm b/v7/src/runtime/unxpth.scm
index 119755af4..446b89083 100644
--- a/v7/src/runtime/unxpth.scm
+++ b/v7/src/runtime/unxpth.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: unxpth.scm,v 14.32 2007/01/05 21:19:28 cph Exp $
+$Id: unxpth.scm,v 14.33 2007/04/15 17:43:08 cph Exp $
 
 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
     1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
@@ -326,15 +326,15 @@ USA.
 			       (reverse!
 				(let loop
 				    ((elements (reverse (cdr directory))))
-				  (if (null? elements)
-				      '()
-				       (let ((head (car elements))
-					     (tail (loop (cdr elements))))
-					 (if (and (eq? head 'UP)
-						  (not (null? tail))
-						  (not (eq? (car tail) 'UP)))
-					     (cdr tail)
-					     (cons head tail)))))))))
+				  (if (pair? elements)
+				      (let ((head (car elements))
+					    (tail (loop (cdr elements))))
+					(if (and (eq? head 'UP)
+						 (pair? tail)
+						 (not (eq? (car tail) 'UP)))
+					    (cdr tail)
+					    (cons head tail)))
+				      '()))))))
 		    (and (not (equal? directory directory*))
 			 (let ((pathname*
 				(pathname-new-directory pathname directory*)))