Last modified: 2009-09-03 09:26:59 UTC
http://en.wikipedia.org/wiki/Fish/ should just open http://en.wikipedia.org/wiki/Fish since "$wgNamespacesWithSubpages[NS_MAIN] = true;"
Better if trailing slashes were always ignored. Ignoring depending on that setting would easily shadow pages.
One note is that the / may be quite legitimately distinct in special page parameters. Eg, there's a significant difference between: http://en.wikipedia.org/wiki/Special:Prefixindex/OS and http://en.wikipedia.org/wiki/Special:Prefixindex/OS/ (Particuarly when doing subpage listings.)
*** This bug has been marked as a duplicate of bug 3368 ***