The Tor Browser / file revision

 // getLineOffsets correctly places the various parts of a ForStatement.

 var g = newGlobal();

 var dbg = Debugger(g);

 dbg.onDebuggerStatement = function (frame) {

     function handler(line) {

         return {hit: function (frame) { g.log += "" + line; }};

     }

     var s = frame.eval("f").return.script;

     for (var line = 2; line <= 6; line++) {

         var offs = s.getLineOffsets(g.line0 + line);

         var h = handler(line);

         for (var i = 0; i < offs.length; i++) {

             assertEq(s.getOffsetLine(offs[i]), g.line0 + line);

             s.setBreakpoint(offs[i], h);

         }

     }

 };

 g.log = '';

 g.eval("var line0 = Error().lineNumber;\n" +

        "function f(n) {\n" +        // line0 + 1

        "    for (var i = 0;\n" +    // line0 + 2

        "         i < n;\n" +        // line0 + 3

        "         i++)\n" +          // line0 + 4

        "        log += '.';\n" +    // line0 + 5

        "    log += '!';\n" +        // line0 + 6

        "}\n" +

        "debugger;\n");

 assertEq(g.log, "");

 g.f(3);

 assertEq(g.log, "235.435.435.436!");