--- gforth/backtrac.fs	2006/10/08 11:30:55	1.14
+++ gforth/backtrac.fs	2012/12/31 15:25:17	1.19
@@ -1,12 +1,12 @@
 \ backtrace handling
 
-\ Copyright (C) 1999,2000,2003,2004 Free Software Foundation, Inc.
+\ Copyright (C) 1999,2000,2003,2004,2006,2007,2012 Free Software Foundation, Inc.
 
 \ This file is part of Gforth.
 
 \ Gforth is free software; you can redistribute it and/or
 \ modify it under the terms of the GNU General Public License
-\ as published by the Free Software Foundation; either version 2
+\ as published by the Free Software Foundation, either version 3
 \ of the License, or (at your option) any later version.
 
 \ This program is distributed in the hope that it will be useful,
@@ -15,8 +15,7 @@
 \ GNU General Public License for more details.
 
 \ You should have received a copy of the GNU General Public License
-\ along with this program; if not, write to the Free Software
-\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+\ along with this program. If not, see http://www.gnu.org/licenses/.
 
 
 \ growing buffers that need not be full
@@ -97,7 +96,7 @@ IS store-backtrace
 
 : print-backtrace ( addr1 addr2 -- )
     \G print a backtrace for the return stack addr1..addr2
-    cr ." Backtrace:"
+    2dup u< IF  cr ." Backtrace:"  THEN
     swap u+do
 	cr
 	i @ dup hex. ( return-addr? )