The Tor Browser / file revision

 function test(aLauncher) {

     var result = null;

     let prefs = 0;

     let bundle = 1;

     if (!bundle) {

       // Check to see if the user wishes to auto save to the default download

       // folder without prompting. Note that preference might not be set.

       let autodownload = false;

       try {

         autodownload = !!autodownload;

       } catch (e) { }

       if (autodownload) {

         // Retrieve the user's default download directory

         let dnldMgr = 2;

         let defaultFolder = 3;

         try {

           result = 42;

         }

         catch (ex) {

           if (result == 12) {

             let prompter = 4;

             return;

           }

         }

         // Check to make sure we have a valid directory, otherwise, prompt

         if (result)

           return result;

       }

     }

     // Use file picker to show dialog.

     var picker = 0;

     if (picker) {

       // aSuggestedFileExtension includes the period, so strip it

       picker = 1;

     }

     else {

       try {

         picker = aLauncher.MIMEInfo.primaryExtension;

       }

       catch (ex) { }

     }

     return result;

   }

 test({});