Smart Middle Click

gBrowser = document.getElementById("content");
gBrowser.addEventListener("click", SMConClick, true);

function fixupAURL(aURL) {
    var str = '^(https?\:|ftp\:|news\:|mailto\:|smb\:' +
             'gopher\:|about\:|file\:|cache\:|javascript\:|' +
             'x\-jsd\:|jar\:|resource\:|data\:)'
    var re = new RegExp(str, 'i');
    if (re.test(aURL)) {
        return aURL;
    }
    else {
        var urifix  = Components.classes['@mozilla.org/docshell/urifixup;1'].getService(Components.interfaces.nsIURIFixup);
        var loc = urifix.createFixupURI(getBrowser().currentURI.spec, 0);
        var host = loc.host, path = loc.path, proto = loc.scheme;
        if (aURL[0] == '/') {
            path = '';
        }
        else {
            path = path.replace(/(.+?\/?)[^\/]+?$/, "$1");
            while (/\.\.\//i.test(aURL)) {
                aURL = aURL.replace(/\.\.\//i, '');
                path = path.replace(/(.+?\/?)[^\/]+?\/$|([^\/]+?\/?)$/, "$1");
            }
            if (path[0] != '/') {
                path = '/' + path;
            }
        }
        return proto + '://' + host + path + aURL;
    }
}

function SMConClick(aEvent) {
    if ( (aEvent.button == 1 || (aEvent.button == 0 && (aEvent.ctrlKey || aEvent.shiftKey)))
                && contentAreaClick2(aEvent) )
        aEvent.stopPropagation();
}

function contentAreaClick2(event)
{
    var target = event.target;
    var linkNode;

    if (target instanceof HTMLAnchorElement ||
            target instanceof HTMLAreaElement ||
            target instanceof HTMLLinkElement)
    {
        if (target.hasAttribute("href"))
            linkNode = target;
    }
    else {
        linkNode = event.originalTarget;
        while (linkNode && !(linkNode instanceof HTMLAnchorElement))
            linkNode = linkNode.parentNode;
        // <a> cannot be nested.  So if we find an anchor without an
        // href, there is no useful <a> around the target
        if (linkNode && !linkNode.hasAttribute("href"))
            linkNode = null;
    }
    var wrapper = null;

    if (linkNode) {
        wrapper = linkNode;

        var is_js = wrapper.href.indexOf('javascript:');
        var pound = wrapper.href.charAt(wrapper.href.length-1);

        // Check if URL has 'javascript:' in it
        if (is_js != -1) {
            var jsParts = wrapper.href.split("'");
            rawHref = jsParts[1];

            if (rawHref) {
                newHref = unescape(fixupAURL(rawHref));
                handleLinkClick(event, newHref, linkNode);
            }
            // If extraction fails, try the onclick attribute
            else if (wrapper.getAttribute("onclick")) {
                var ocParts = wrapper.getAttribute("onclick").split("'");
                rawHref = ocParts[1];

                if (rawHref) {
                    newHref = unescape(fixupAURL(rawHref));
                    handleLinkClick(event, newHref, linkNode);
                }
            }

            return true;
        }
        // Check if URL ends in '#'
        else if (pound == '#') {
            var ocParts = wrapper.getAttribute("onclick").split("'");
            rawHref = ocParts[1];

            if (rawHref) {
                newHref = unescape(fixupAURL(rawHref));
                handleLinkClick(event, newHref, linkNode);
            }

            return true;
        }
    }

    return false;
}