diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/jaeger/testBug550743.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/jaeger/testBug550743.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+expected = '';
+
+function g(code) {
+  f = Function(code);
+  gen = f();
+  gen.next();
+  try { gen.next(); } catch (ex) { expected = ex.toString() }
+}
+
+g("\
+  yield this.__defineGetter__('x', function(){ return z }); \
+  let z = new String('hi'); \
+  ");
+
+eval();
+gc();
+
+str = x;
+
+assertEq(expected, "[object StopIteration]");
+assertEq(str.toString(), "hi");