diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/eif-generator.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/eif-generator.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,54 @@
+// |jit-test| debug
+function f() {
+    let (x = 1) {
+        while (true) {
+            yield evalInFrame(0, "x");
+            x++;
+            let (y = 1) {
+                yield evalInFrame(0, "++y");
+                yield evalInFrame(0, "++y");
+            }
+        }
+    }
+}
+
+var gen = f();
+assertEq(gen.next(), 1);
+assertEq(gen.next(), 2);
+gc();
+assertEq(gen.next(), 3);
+gc();
+assertEq(gen.next(), 2);
+assertEq(gen.next(), 2);
+gc();
+assertEq(gen.next(), 3);
+gc();
+assertEq(gen.next(), 3);
+assertEq(gen.next(), 2);
+gc();
+assertEq(gen.next(), 3);
+gen = null;
+gc();
+
+function g() {
+    let (x = 1) {
+        while (true) {
+            var inner = function (inc) { x += inc; return evalInFrame(0, "x") };
+            assertEq(inner(0), x);
+            yield inner;
+            assertEq(inner(0), x);
+        }
+    }
+}
+
+var gen = g();
+var g1 = gen.next();
+var g2 = gen.next();
+gc();
+assertEq(g1(1), 2);
+assertEq(g2(1), 3);
+gc();
+assertEq(g1(1), 4);
+assertEq(g2(1), 5);
+gen = g1 = g2 = null;
+gc();