--- gforth/engine/dblsub.c	1997/05/21 20:40:06	1.1
+++ gforth/engine/dblsub.c	2006/10/23 08:45:00	1.7
@@ -1,7 +1,7 @@
 /* some routines for double-cell arithmetic
    only used if BUGGY_LONG_LONG
 
-   Copyright (C) 1996 Free Software Foundation, Inc.
+   Copyright (C) 1996,2000,2003 Free Software Foundation, Inc.
  * Copyright (C) 1995  Dirk Uwe Zoller
  *
  * This library is free software; you can redistribute it and/or
@@ -16,7 +16,7 @@
  *
  * You should have received a copy of the GNU Library General Public
  * License along with this library; if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 
  This has been adapted from pfe-0.9.14
  */
@@ -81,6 +81,10 @@ UDCell umdiv (UDCell u, UCell v)
   UCell q = 0, h = u.hi, l = u.lo;
   UDCell res;
 
+  if (v==0)
+    throw(BALL_DIVZERO);
+  if (h>=v)
+    throw(BALL_RESULTRANGE);
   for (;;)
     {
       if (c || h >= v)
@@ -112,8 +116,14 @@ DCell smdiv (DCell num, Cell denom)	/* s
   if (denomsign < 0)
     denom = -denom;
   res = UD2D(umdiv (D2UD(num), denom));
-  if ((numsign^denomsign)<0)
+  if ((numsign^denomsign)<0) {
     res.lo = -res.lo;
+    if (((Cell)res.lo) > 0) /* note: == 0 is possible */
+      throw(BALL_RESULTRANGE);
+  } else {
+    if (((Cell)res.lo) < 0)
+      throw(BALL_RESULTRANGE);
+  }
   if (numsign<0)
     res.hi = -res.hi;
   return res;
@@ -124,14 +134,18 @@ DCell fmdiv (DCell num, Cell denom)	/* f
   /* I have this technique from Andrew Haley */
   DCell res;
   Cell denomsign=denom;
+  Cell numsign;
 
   if (denom < 0) {
     denom = -denom;
     num = dnegate(num);
   }
-  if (num.hi < 0)
+  numsign = num.hi;
+  if (numsign < 0)
     num.hi += denom;
   res = UD2D(umdiv(D2UD(num),denom));
+  if ((numsign^((Cell)res.lo)) < 0)
+    throw(BALL_RESULTRANGE);
   if (denomsign<0)
     res.hi = -res.hi;
   return res;