The Tor Browser / file revision

 var objs;

 function init()

 {

     objs = new Object();

     var x = new Object();

     objs.root1 = x;

     objs.root2 = new Object();

     x.ptr = new Object();

     x = null;

     /*

      * Clears out the arena lists. Otherwise all the objects above

      * would be considered to be created during the incremental GC.

      */

     gc();

 }

 /*

  * Use eval here so that the interpreter frames end up higher on the

  * stack, which avoids them being seen later on by the conservative

  * scanner.

  */

 eval("init()");

 gcslice(0);

 selectforgc(objs.root2);

 gcslice(1);

 objs.root2.ptr = objs.root1.ptr;

 objs.root1.ptr = null;

 gcslice();