As has been poked around the lists for a while, there's some interest in more active use of protocol-relative URLs (eg, '//upload.wikimedia.org/path/to/file.png' instead of 'http://upload.wikimedia.org/path/to/file.png').
Touted benefits include:
- ability to reference on-site links, sister-site links, and sister-site media references with the current protocol without having to render and cache separately for HTTP and HTTPS (but this requires that the URLs be otherwise identical! Would not be compatible with our current secure.wikimedia.org scheme, for instance)
- saving 5-6 bytes each for many of those external URL references
Browser compatibility seems reasonably stable for those who have been testing it, but there are lots of gotchas as MediaWiki doesn't cleanly support this yet.
A few notes offhand:
- wfExpandUrl and numerous other places assume any URL starting with "/" is relative to the current _host_ and will prepend '$wgServer' to it.
- there will be various places where we need to explicitly use a complete URL including the protocol, such as when creating emails, HTML or RSS feeds to use externally
- Uses of {{fullurl:}} {{SERVER}} etc in wikitext assume that the result is ok for use in wikitext as links; currently I don't believe these will get picked up.
In general we also probably want MW to know when it needs to make an HTTP reference and when an HTTPS reference, and generate those explicitly at times. (Eg a login link should always be HTTPS; some interwikis might take both HTTP and HTTPs while others might only take one or the other.)
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=52253 / T54253