Posted by: Dakusan
« on: September 28, 2009, 05:31:58 am »Originally posted on: 09/14/08
We recently moved one of our important web server clients to a newly acquired server (our 12th server at ThePlanetThePlanet [Used to be called EV1Servers, and before that RackShack], one of, if not the largest, server-farm hosting company in the states). A bad problem cropped up on his site in the form of a PHP script (CaRP) that deals with parsing XML.
The problem was that whenever the XML was parsed and then returned, all XML entities (escaped XML characters like “>” “<” and “"”) were removed/deleted. I figured the problem had to do with a bad library, as the code worked perfectly on our old server, and the PHP settings on both were almost identical, but I wasn’t sure which one. After an hour or two of manipulating the code and debugging, I narrowed it down to which XML function calls had the problem, and that it was definitely not the scripts themselves. The following code demonstrates the problem.
$MyXml=xml_parser_create(strtoupper('ISO-8859-1'));
xml_parser_set_option($MyXml,XML_OPTION_TARGET_ENCODING,'ISO-8859-1');
xml_parse_into_struct($MyXml, $MyXMLData, $MyData);
print htmlentities($MyData[0]['value']);
img test=awhile it should have outputted the following:
<img test="a"
I went with a hunch at this point and figured that it might be the system’s LibXML libraries, so I repointed them away from version 2.7.1, which appears to be buggy, to an older version that was also on the system, 2.6.32. And low and behold, things were working again, yay :-D.
Technical data (This is a cPanel install): In “/opt/xml2/lib/” delete the symbolic links “libxml2.so” & “libxml2.so.2” and redirect them as symbolic links to “libxml2.so.2.6.32” instead of “libxml2.so.2.7.1”.
