Fix XSS vulnerability in _mbox argument handling (#1490417)

Aleksander Machniak

2015-05-30 b782815dacda55eee6793249b5da1789256206fc

 program/include/rcmail_output.php

@@ -28,6 +28,7 @@
abstract class rcmail_output extends rcube_output
{
    const JS_OBJECT_NAME = 'rcmail';
    const BLANK_GIF      = 'R0lGODlhDwAPAIAAAMDAwAAAACH5BAEAAAAALAAAAAAPAA8AQAINhI+py+0Po5y02otnAQA7';

    public $type = 'html';
    public $ajax_call = false;