Fix Firefox double-history-entry problem.

     */

    push: function(token, opts) {

        token = this.cleanUrl(token);

        if (!/^#!?/.test(token)) {

            token = "#!"+token;

        }

        if (!/^!/.test(token)) {

            token = "!"+token;

        }

        // Firefox sometimes has %21 instead of !.

        // This happens with URL-s inside normal links on page.

        //

        // So at first round history entry beginning with %21 is added

        // which triggers navigate() to load the right page, but this

        // comes around in circle to here and pushes a new entry

        // beginning with "!" and so a double-entry would be added

        // because the new entry differs from previous although they

        // are really the same.

        //

        // To prevent this, check that previous equivalent entry isn't

        // equivalent to new one.

        if (Ext.util.History.getToken().replace(/^%21/, "!") !== token) {

            Ext.util.History.add(token);

        }

    },

    /**

     * Given a URL, removes anything before a #

     * Given a URL, removes anything up to # (including #)

     */

    cleanUrl: function(url) {

        return url.replace(/^[^#]+#/, '#');

        return url.replace(/^[^#]*#/, '');

    }

});