If a browser receives a client error (4xx) message upon sending a HTTP request, the server typically includes a diagnostic message. The "404" pages are well known to most people. According to the specification (RFC2068, section 10.4), "the server SHOULD include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. These status codes are applicable to any request method. User agents SHOULD display any included entity to the user." For 404 and 403 messages, Safari does display the diagnostic webpage. However, for 401 (Unauthorized), it does not, but shows the preceeding page. Safari 'SHOULD' do show the diagnostic page instead. now, the user misses important information. Example to reproduce: 1. Open Safari 2. Go to http://www.science.uva.nl/research/air/network/ 3. Press cancel Expected results: I would exepct to see the diagnostic page, which you can get with "curl http://www.science.uva.nl/research/air/network/" Actual results: I see the previously visited page (or a blank page if I did not visit a page before). Work around: There is no work-around, other then using an other browser. Isolation: This behaviour does occur with 401 pages, not with 403 or 404 pages. I haven't tried with other result codes. This bug has been reported as rdar:3631782 with Apple, in june 2004. I hope it does get some more attention here.
Confirmed, an annoying little bug this one :)
My patch for bug 13075 fixes this, too.
Fixed on Mac in <http://trac.webkit.org/changeset/63095>. A Windows Safari fix is in closed source code.
*** Bug 47886 has been marked as a duplicate of this bug. ***