Array.prototype.toJSON requires double parsing after stringify

[Matan Shiloah]

When prototype.js loads on page, stringifying an array required double parsing to convert back to array.
F.E:
var a = [ 1 ];
var b = JSON.stringify(a); // will output ""[1]"" (string of array to string) instead of "[1]" (array to string)
var c = JSON.parse(b); // will output "[1]" (array to string) instead of [1] (array)
JSON.parse(c); // will output [1] (array).
Found on potora.jp.

[Andrew Dupont]

This is an issue from a very old version of Prototype. Updating to 1.7 should fix this.