diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_6/Generators/delegating-yield-10.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_6/Generators/delegating-yield-10.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,49 @@
+// Errors accessing next, done, or value don't cause an exception to be
+// thrown into the iterator of a yield*.
+
+function* g(n) { for (var i=0; i<n; i++) yield i; }
+function* delegate(iter) { return yield* iter; }
+
+var log = "", inner, outer;
+
+// That var is poisoooooon, p-poison poison...
+var Poison = new Error;
+
+function log_calls(method) {
+    return function () {
+        log += "x"
+        return method.call(this);
+    }
+}
+
+function poison(receiver, prop) {
+    Object.defineProperty(receiver, prop, { get: function () { throw Poison } });
+}
+
+// Poison inner.next.
+inner = g(10);
+outer = delegate(inner);
+inner.throw = log_calls(inner.throw);
+poison(inner, 'next')
+assertThrowsValue(outer.next.bind(outer), Poison);
+assertEq(log, "");
+
+// Poison result value from inner.
+inner = g(10);
+outer = delegate(inner);
+inner.next = function () { return { done: true, get value() { throw Poison} } };
+inner.throw = log_calls(inner.throw);
+assertThrowsValue(outer.next.bind(outer), Poison);
+assertEq(log, "");
+
+// Poison result done from inner.
+inner = g(10);
+outer = delegate(inner);
+inner.next = function () { return { get done() { throw Poison }, value: 42 } };
+inner.throw = log_calls(inner.throw);
+assertThrowsValue(outer.next.bind(outer), Poison);
+assertEq(log, "");
+
+// mischief managed.
+if (typeof reportCompare == "function")
+    reportCompare(true, true);