Hi Frustratedtaco, that first item on the drop-down is really just for your information: even if it is weren't there, the same thing would happen when you press Enter.

That said, you can hide that line on the bar using an add-on and a custom style rule.

(1) First install the Stylish extension: https://addons.mozilla.org/firefox/addon/stylish/

(2) After restarting Firefox to activate the extension, install this custom style rule: https://userstyles.org/styles/122394/url-bar-tweaks-remove-visit-search-scroll-bar

If you are having problems with Firefox doing random things with your input into the address bar, it could be the configuration of your default search engine and/or how Firefox looks up "one word" address bar entries (DNS resolution). If the behavior seems odd, could you describe it in more detail?

I'd rather not install an extension to solve a problem that the browser itself previously had a setting for.

As for what it's doing, typing in "sq", the first two letters of a site I frequent, and hitting enter brings me to www.singaporeair.com, for a random example. That makes no sense.

Frustratedtaco said

As for what it's doing, typing in "sq", the first two letters of a site I frequent, and hitting enter brings me to www.singaporeair.com, for a random example. That makes no sense.

Interesting -- SQ is the two letter code that appears before Singapore Airlines flight numbers, so it's not completely random.

But normally I would only expect to see what you see if you happened to have a bookmark for the site and had assigned sq as the keyword for the bookmark. It really shouldn't happen under any other circumstances.

Instead, you either would go to the domain shown as you type (in-URL-bar autofill feature) or get search results from your default search engine. (When I type sq and press Enter, I get Google results, with the top result being Square, the payments company.)

Do you use any extensions that might modify how the address bar works, such as the old Keyword Search extension?

Do you recall changing any of the preferences that govern search vs. DNS lookup and the order of the two?

Frustratedtaco said

I'd rather not install an extension to solve a problem that the browser itself previously had a setting for.

Okay, you can create a userChrome.css file instead, and paste the custom style rule in there. You can click the "View CSS" link in that page to display the CSS rules and then create a userChrome.css file to apply it. This article has more information on how to do that: http://kb.mozillazine.org/UserChrome.css

I don't use any extensions whatsoever, aside from adblock and I'm sure that's unrelated.

If I recall correctly, the only settings I ever changed in about:config were to disable the search in the address bar and the subsequent visit function. I can't recall changing anything else. If it behaved the way you described, I wouldn't really have a problem. Hmmm.

For address bar search, you could check these:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste keyw and pause while the list is filtered

(3) If the keyword.enabled preference is bolded and "user set" to false, double-click it to restore the default value of true

(4) In the search box above the list, type or paste fix and pause while the list is filtered

(5) If the browser.fixup.dns_first_for_single_words preference is bolded and "user set" to true, double-click it to restore the default value of false

Thank you. I'd rather do without the address bar searching entirely, but Google is preferable to whatever else was happening.

One thing that could be happening was what I'll call dishonest DNS. Obviously there's no sq as a domain name, so the DNS service sends you somewhere else, which could be to a search page or apparently wherever it feels like. If you enter an unregistered domain in the address bar and press Enter, do you get any unusual results page? For example, this --

http://www.jeffersonscher.vip/

-- should return server not found, if the DNS service is honest.