diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug620838.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug620838.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,22 @@
+function g() {
+    return "global";
+}
+
+function q(fun) {
+    return fun();
+}
+
+function f(x) {
+    if (x) {
+        function g() {
+            return "local";
+        }
+        var ans = q(function() {
+            return g();
+        });
+    }
+    g = null;
+    return ans;
+}
+
+assertEq(f(true), "local");