Last modified: 2011-04-14 15:13:03 UTC
As some ISPs and possibly some esoteric browsers still usurp 404 messages, a 404 status code should never be served as the result of a Search. For example, if you put in User:Someuser where the user exists but has no user page, you are automatically taken to the user page, but given a 404. If their ISP/Browser sucks, they then can't check the user's contribs or talk page. The same logic that applies the redirects should possibly also be used to determine the status (in a mutually exclusive way). Annoying, incoming interwiki links probably cannot be handled correctly, without referer sniffing.
On general principle, probably should not be returning a 404 for a user page for an existing user/IP address.
(In reply to comment #1) > On general principle, probably should not be returning a 404 for a user page > for an existing user/IP address. Updating summary for more accuracy. This can be resolved by either not sending users to these via Search [go] and p-personal link clicking, /or/ by not serving 404 for them (as per populated red categories or shared repository images). Note that either all user/user_talk pages will have to check if the user exists before search 30x redirects users to these pages, or 404 should stop being served for all user/user_talk pages (or in fact, just ditch the 404 serving completely).