The Tor Browser / file revision

 // var statements in strict evalWithBindings code behave like strict eval.

 var g = newGlobal();

 var dbg = new Debugger(g);

 var hits = 0;

 dbg.onDebuggerStatement = function (frame) {

     assertEq(frame.evalWithBindings("var i = a*a + b*b; i === 25;", {a: 3, b: 4}).return, true);

     hits++;

 };

 g.eval("'use strict'; debugger;");

 assertEq(hits, 1);

 assertEq("i" in g, false);

 g.eval("function die() { throw fit; }");

 g.eval("Object.defineProperty(this, 'i', {get: die, set: die});");

 g.eval("'use strict'; debugger;");

 assertEq(hits, 2);