ensure that media referenced in posts being exported are also included

[pbiron]

If the export is not for "All content", then there are at least 2 cases where this currently does not happen:

1. when the post_content of a post being exported contains a gallery shortcode
2. when the post_content of a post being exported contains an <img src='xxx'> or <a href='xxx'> reference to the media

Both cases are relatively easy (tho, potentially computationally expensive) to fix, but before doing so I want to think about it some more to see if I can come up with any other cases where it happens and fix them all at one.

Note: The standard exporter also has this problem.

[dseomn]

The audio, playlist, and video shortcodes are similar to gallery, I think. There's also the source html element.

[pbiron]

@desomn Thanx!!

I was going to ask on WordPress Importer Redux: Issue 41 if there were any other cases in the importer that should be handled like [gallery] and make sure I covered them in the exporter.

For HTML5's <source>, <audio>, etc my thoughts are to handle them exactly like <img> and <a href>...that is, via a regex that matches any text that appears to be media.