code: function(a, b) {
          if ( b === '' ) { return true; }
          if ( b.startsWith('about:') ) { return false; }
          let pos = a.indexOf('://');
          if ( pos === -1 ) { return false; }
          a = a.slice(pos);
          pos = b.indexOf('://');
          if ( pos !== -1 ) {
              b = b.slice(pos);
          }
          return b !== a;
      }
docs: https://github.com/gorhill/uBlock/commit/1d448b85b2931412508aa01bf899e0b6f0033626#commitcomment-14944764 See if two URLs are different, disregarding scheme -- because the scheme can be unilaterally changed by the browser. https://github.com/gorhill/uBlock/issues/1378 Maybe no link element was clicked. https://github.com/gorhill/uBlock/issues/3287 Do not bail out if the target URL has no hostname.