FireTrimURL.uc.js

location.href === "chrome://browser/content/browser.xul" && (function(){
    
    "use strict";
    
    if(typeof fireTrimURL !== "undefined") return;
    
    var fireTrimURL = {
        
        init: function() {
            gBrowser.addProgressListener(this);
        },

        uninit: function() {
            gBrowser.removeProgressListener(this);
        },

        urlbar: document.querySelector("#urlbar"),
        
        processNewURL: function(aURI) {
            if(/\s+/g.test(this.urlbar.value)){
                var newURL = this.urlbar.value = this.urlbar.value.replace(/\s+/g,"");
                var h = /(http:\/\/|https:\/\/)((\w|=|\?|\.|\/|&|-)+)/g;
                gBrowser.contentDocument.location.href = h.test(newURL) ?
                newURL : "http://"+newURL;
            }
        },

        QueryInterface: XPCOMUtils.generateQI(["nsIWebProgressListener",
                                               "nsISupportsWeakReference"]),

        onLocationChange: function(aProgress, aRequest, aURI) {
            this.processNewURL(aURI);
        }
    };
    
    window.fireTrimURL = fireTrimURL;
    fireTrimURL.init();
    
})();