User Agent: Mozilla/5.0 (Windows NT 6.1; rv:14.0) Gecko/20100101 Firefox/14.0.1 Build ID: 20120713134347 Steps to reproduce: make sure the "browser.urlbar.autoFill" is TRUE. 1,type this url in the address bar "https://www.google.com.hk/#hl=zh-CN&newwindow=1&safe=strict&site=&source=hp&q=%E5%95%8A" then you will see "https://www.google.com.hk/#hl=zh-CN&newwindow=1&safe=strict&site=&source=hp&q=啊", Google will add some other params at the end of the url, so finally, it will looks like this "https://www.google.com.hk/#hl=zh-CN&newwindow=1&safe=strict&site=&source=hp&q=啊&fp=f389c5f761e0798d" 2, remove params which at the end of character "啊", hit enter. 3, repeate above steps several times(i try this for 3 times, then i got the answer) Actual results: address bar will show url like this: "https://www.google.cgoogle.com.hk/#hl=zh-CN&newwindow=1&safe=strict&site=&source=hp&q=啊" when I turn the "browser.urlbar.autoFill" to FALSE, this problem was solved. Expected results: So I think this may be caused by the "firefox 14' address bar autofill" mechanism.

Confirmed in Firefox14, 15beta, Aurora16.0a2 and Nighlty170a1 Regression window(m-c) Good: http://hg.mozilla.org/mozilla-central/rev/7bf0125b26b5 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120601035703 Bad: http://hg.mozilla.org/mozilla-central/rev/305cd10b57d2 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120601055003 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=7bf0125b26b5&tochange=305cd10b57d2 Suspected: Bug 720081

In local build Lastr Good: 59409e2655ca First Bad :960b80d99b4a Triggered by 960b80d99b4a Marco Bonardo — Bug 720081 - Part 2: inline autocomplete should respect protocol and www prefix r=dietrich

This sounds like a pretty unfortunate user-affecting regression that we'll want to try and get a fix for this into Beta if possible. I would assign this to Marco but he's away until the 12th so passing to Gavin to determine who might be able to take this on.