In the context of the XHTML-conform embedding of Google Maps, I encountered two problems (again): When I tried to insert the JavaScript with the CDATA section, WordPress got under my feet with its usually so comfortable automatic formatting functions. The end marker

/* ]]> */

suddenly became:

/* ]]> */

A line in the file wp-includes/post-template.php is to blame for this, which reads:

$content = str_replace(']]>', ']]>', $content);

It’s a mystery to me what this line should ever be good for at all. It is also a mystery to me why the whole thing hasn’t been implemented as a filter that you could turn off when needed. For two years already, several people have been asking for this line to be removed or realized some other way. We can only wait and hope that one far day, this will be changed in a future WordPress release.

In the meantime, there is no other choice but to simpy comment the cited line – even though I don’t appreciate solutions that require messing about with the source code. After that, the CDATA sections work fine – or at least their definition does.

Now, CDATA sections are usually being inserted for only one reason, namely for being able to use characters like <, > etc. without having to convert them into HTML entities. This way, you can for example use HTML inside of a JavaScript without the browser getting irritated by it.
Wordpress however still converts all concerning characters inside the CDATA section in HTML entities. This is caused by the function wpautop() which normally makes our life much easier by converting all the special characters in a post into HTML entities for us. In this special case however, we actually don’t want them to be converted! So we have to turn off the filter wpautop() somehow.

But luckily, there is a plugin for almost everything – including this. It’s called “TextControl” and can be obtained here. By the way, it is even being recommended officially for the use of JavaScript in WordPress posts. With this plugin, you can disable automatic formatting for each post individually or blog-wide. To turn off the conversion of special characters you only have to select “No Character Encoding” instead of “Default (wptexturize)” from the second dropdown menu.