Description:
------------
json_encode ignores simplexml cdata fields and returns a blank string instead of cdata may be related to https://bugs.php.net/bug.php?id=54632&edit=2

Test script:
---------------
<?php

$s = <<<EOT
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Errors>
	<Error>
	<ErrorId>XML999</ErrorId>
	<ErrorText><![CDATA[cvc-complex-type: Invalid content was found starting with XXX. One of '{XXX}' is expected.]]></ErrorText>
	</Error>
</Errors>
</Response>
EOT;

$xml = simplexml_load_string($s);

echo $xml->Errors->Error->ErrorId.PHP_EOL;
echo $xml->Errors->Error->ErrorText.PHP_EOL;

echo json_encode($xml,JSON_PRETTY_PRINT);


Expected result:
----------------
XML999
cvc-complex-type: Invalid content was found starting with XXX. One of '{XXX}' is expected.
{
    "Errors": {
        "Error": {
            "ErrorId": "XML999",
            "ErrorText": "cvc-complex-type: Invalid content was found starting with XXX. One of '{XXX}' is expected."
        }
    }
}

Actual result:
--------------
XML999
cvc-complex-type: Invalid content was found starting with XXX. One of '{XXX}' is expected.
{
    "Errors": {
        "Error": {
            "ErrorId": "XML999",
            "ErrorText": {

            }
        }
    }
}