User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:34.0) Gecko/20100101 Firefox/34.0 (Beta/Release) Build ID: 20140723030202 Steps to reproduce: With the latest Nightly, Type http://localhost/ in the location bar. Actual results: Th browser tried to open http://www.localhost.com/. Expected results: It should open http://localhost/. It works fine with Aurora.

I can't reproduce this on the same nightly on OS X 10.9.4. Have you checked a clean profile? Can you copy/paste all your prefs starting with "browser.fixup" from about:config? (take care to censor any private data but let me know of what kind, ie "I removed some browser.fixup.domainwhitelist entries" or whatever.

(oh, and are you using a proxy of some description?)

I can reproduce with a clean profile. I am behind my company's proxy (Squid).

(In reply to Pierre Rudloff from comment #3) > I can reproduce with a clean profile. > > I am behind my company's proxy (Squid). If you use a build from http://ftp.mozilla.org/pub/mozilla.org/firefox/try-builds/sworkman@mozilla.com-8e3a63e3afd7/try-macosx64/ or the upcoming nightly (the mac version should be ready within an hour or so), can you still reproduce?

I can't reproduce with http://ftp.mozilla.org/pub/mozilla.org/firefox/try-builds/sworkman@mozilla.com-8e3a63e3afd7/try-macosx64/.

(In reply to Pierre Rudloff from comment #5) > I can't reproduce with > http://ftp.mozilla.org/pub/mozilla.org/firefox/try-builds/sworkman@mozilla. > com-8e3a63e3afd7/try-macosx64/. Great! This should be fixed in the upcoming nightly, then.