MediaWiki r98216 - Code Review

 		var targetBaseUrl === currentBaseUrl,
 		currentBaseUrl = window.location.href.split("#")[0];

 		// Compatibility with 1.17, 1.18
 		|| mw.config.get( 'wgServer' ) + targetBaseUrl === currentBaseUrl
+		// Compatibility with protocol-relative URLs
+		|| window.location.protocol + mw.config.get( 'wgServer' ) + targetBaseUrl === currentBaseUrl

Doesn't work as expected under 1.17wmf1 (ie. commons and others)

var targetBaseUrl = mw.util.wikiGetlink(data.redirect.pageName);

this is either /wiki/User:Foo (1.18+) or (http:)//example.org/wiki/User:Foo (1.17), which is why the first fallback prepending wgServer was added in r91853.

now with the variable protocol (relative on wmf-production, non-relative in development and other 'normal' wikis), we need two, not one, extra fallback.

The following is also needed:

// Compatibility with protocol-relative URLs on 1.17
|| window.location.protocol + targetBaseUrl === currentBaseUrl