(float_arith_driver): Detect division by zero in advance.

(arith_driver, Frem): Likewise.

1 files changed, 18 insertions, 4 deletions

diff --git a/src/data.c b/src/data.c
index e56e30ed6df..c5564158984 100644
--- a/src/data.c
+++ b/src/data.c
@@ -1550,8 +1550,7 @@ enum arithop
 extern Lisp_Object float_arith_driver ();
 
 Lisp_Object
-arith_driver
-  (code, nargs, args)
+arith_driver (code, nargs, args)
      enum arithop code;
      int nargs;
      register Lisp_Object *args;
@@ -1607,7 +1606,12 @@ arith_driver
         case Amult: accum *= next; break;
         case Adiv:
           if (!argnum) accum = next;
-          else accum /= next;
+          else
+            {
+              if (next == 0)
+                Fsignal (Qarith_error, Qnil);
+              accum /= next;
+            }
           break;
         case Alogand: accum &= next; break;
         case Alogior: accum |= next; break;
@@ -1668,7 +1672,11 @@ float_arith_driver (accum, argnum, code, nargs, args)
           if (!argnum)
             accum = next;
           else
-            accum /= next;
+            {
+              if (next == 0)
+                Fsignal (Qarith_error, Qnil);
+              accum /= next;
+            }
           break;
         case Alogand:
         case Alogior:
@@ -1746,6 +1754,9 @@ Both must be numbers or markers.")
 
       f1 = XTYPE (num1) == Lisp_Float ? XFLOAT (num1)->data : XINT (num1);
       f2 = XTYPE (num2) == Lisp_Float ? XFLOAT (num2)->data : XINT (num2);
+      if (f2 == 0)
+        Fsignal (Qarith_error, Qnil);
+
 #if defined (USG) || defined (sun) || defined (ultrix) || defined (hpux)
       f1 = fmod (f1, f2);
 #else
@@ -1760,6 +1771,9 @@ Both must be numbers or markers.")
   CHECK_NUMBER_COERCE_MARKER (num2, 1);
 #endif /* not LISP_FLOAT_TYPE */
 
+  if (XFASTINT (num2) == 0)
+    Fsignal (Qarith_error, Qnil);
+
   XSET (val, Lisp_Int, XINT (num1) % XINT (num2));
   return val;
 }