The Tor Browser / file revision

 // Code runs fine if do-nothing breakpoints are set on every line.

 var g = newGlobal();

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

            "function gcd(a, b) {\n" +       // line0 + 1

            "    if (a > b)\n" +             // line0 + 2

            "            return gcd(b, a);\n" +  // line0 + 3

            "    var c = b % a;\n" +         // line0 + 4

            "    if (c === 0)\n" +           // line0 + 5

            "            return a;\n" +          // line0 + 6

            "    return gcd(c, a);\n" +      // line0 + 7

            "}\n");                          // line0 + 8

 g.eval(src);

 var dbg = Debugger(g);

 var hits = 0 ;

 dbg.onDebuggerStatement = function (frame) {

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

     var offs;

     for (var lineno = g.line0 + 2; (offs = s.getLineOffsets(lineno)).length > 0; lineno++) {

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

             s.setBreakpoint(offs[i], {hit: function (f) { hits++; }});

     }

     assertEq(lineno > g.line0 + 7, true);

     assertEq(lineno <= g.line0 + 9, true);

 };

 g.eval("debugger;");

 assertEq(g.gcd(31 * 7 * 5 * 3 * 2, 11 * 3 * 3 * 2), 6);

 assertEq(hits >= 18, true);