Fix undef warning in Math::BigInt

diff --git a/lib/Math/BigInt.pm b/lib/Math/BigInt.pm
index f76f261..422dca4 100644 (file)
--- a/lib/Math/BigInt.pm
+++ b/lib/Math/BigInt.pm
@@ -214,7 +214,7 @@ sub mul { #(*int_num_array, *int_num_array) return int_num_array
     for $x (@x) {
       ($car, $cty) = (0, $[);
       for $y (@y) {
-       $prod = $x * $y + $prod[$cty] + $car;
+       $prod = $x * $y + ($prod[$cty] || 0) + $car;
        $prod[$cty++] =
          $prod - ($car = int($prod * 1e-5)) * 1e5;
       }