Can you explain the hooks or filters WordPress applies when saving a post which remove an absolute URL and makes it a relative URL?
My site consumes an RSS feed, that I pay for, which includes a tracking pixel at the end of each post. The tracking pixel is in an IMG tag with a bunch of parameters after it - something like this:
<img src='http://example.com/trackingPixel.gif?param1=123abc456' />
The tracking pixel changes for each item in the RSS feed (after 'param1' in the example), so I can't just add the pixel myself - I have to use the one that's in the feed's content. The problem is WordPress replaces the tracking pixel with a relative URL like this:
The modified URL makes the tracking pixel useless.
I have been looking for a workaround for hours now - I checked default filters, removed default filters, modified $allowedtags global variable, commented out the wp_strip_all_tags function, went through the theme, RSS reader, etc, etc.