Anyone here have any experience with protocol relative URLs, that is URLs of the form "//some.domain.org/file.ext"? URLs of this form are uncommon but appear compliant with RFC 1808.
A possible application of protocol relative URLs for MediaWiki is that they could be used remove the problem of needing duplicate parsings of pages containing external (and cross-domain) links in order to support HTTPS. With that issue out of the way the only impediment to high performance SSL is connection setup which can be addressed with dedicated crypto cards or crypto enhanced CPUs like Ultrasparc T1/T2.
I've confirmed protocol relatives they work in the browsers I have ready access to. Googling around I found http://nedbatchelder.com/blog/200710/httphttps_transitions_and_relative_urls... which claims "The HTML 2 spec references RFC 1808 which describes this behavior, and was written in 1995. I know this syntax works in IE6, IE7, FF2, and Safari 2 and 3. I don't know of any browsers in which it doesn't work."
Anyone here have practical experience with URLs of this form?