Filed under ‘Annoying things I keep forgetting how to fix…’: Out of the box, Firefox has a feature designed to help people mis-typing URLs in the browser bar. It’s described in detail here, but briefly, if a URL fails to resolve, Firefox trys a couple of permutations of the URL to try find what you -might have- really intended, appending a .com and/or prefixing a www. to the host name portion of the URL to see if they resolve. This feature was introduced way back in the early versions of Firefox, and has been annoying developers ever since. The feature means that often-times when a server running on localhost fails to respond, Firefox decides to try localhost.com and/or www.localhost.com. Now once you’ve fixed the problem with the server, you hit the reload button on Firefox, but it still doesn’t work, but this time it’s because Firefox has changed your URL to point at this bogus localhost.com. Annoying!!! To disable this ‘feature’ do the following:
about:config in the browser barbrowser.fixup.alternate.enabled in the search box that appearsbrowser.fixup.alternate.enabled that appears in the filtered list below and choose Toggle to set the value to false