I've inherited a site which has a mobile version. Let's call it qqq.com. It has a Varnish server in front of it to cache the pages. But it seems the Varnish server is also detecting mobile requests, and changing the URL to m.qqq.com.
The WP install is then switching to the qqq-mobile theme, instead of the qqq theme.
How would you do that? I'm trying to locate the code that does this, so I can do the same thing on my local dev instance.
Thanks for your help.