Error on decrypting encrypted VMs about phpvirtualbox

[ams-tschoening]

I've investigated further and the first dialogue above results in the following data being sent to the server:

{"fn":"mediumChangeEncryption","params":{"medium":"...","id":"...","old_password":"...","cipher":"","password":""},"persist":null}:

which leads to the following code in the server:

	    /* @var $progress IProgress */
	    $progress = $m->changeEncryption($args['old_password'],
	            $args['cipher'], $args['password'], $args['id']);

    public function changeEncryption($arg_currentPassword, $arg_cipher, $arg_newPassword, $arg_newPasswordId)
    {
        $request = new stdClass();
        $request->_this = $this->handle;
        $request->currentPassword = $arg_currentPassword;
        $request->cipher = $arg_cipher;
        $request->newPassword = $arg_newPassword;
        $request->newPasswordId = $arg_newPasswordId;
        $response = $this->connection->__soapCall('IMedium_changeEncryption', array((array)$request));
        return new IProgress ($this->connection, $response->returnval);
    }

So it's pretty clear that simply all available data is forwarded to VirtualBox and while cipher and password are empty, the password Id is not, therefore forwarded and results in the error thrown by VirtualBox.

So how to fix this? I think the easiest way is to directly check in this function if the cipher and new password are empty and don't forward the password ID in that case. Seems better than to provide another API only for decryption.