wp_upload_dir() urls wrong

Hi all,

Out-of-the-box this plugin doesn’t map media urls to the mapped domain.
For example, if my network is subdomain.domain.com and a site on the network is site2.domain.com, the media URLs will still be site2.subdomain.domain.com.

I’m using the following fix:
add_filter( ‘wp_get_attachment_url’, ‘domain_mapping_post_content’ );

Found here:
http://ww.wp.xz.cn/support/topic/small-patch-for-next-update-media-file-urls?replies=8

In my theme, there are a few places where the media URLs are gathered using wp_upload_dir(). However, they are site2.subdomain.domain.com, which causes problems.

Is there a way I can apply the fix to the URLs (url and baseurl) returned by wp_upload_dir()?

http://ww.wp.xz.cn/plugins/wordpress-mu-domain-mapping/