diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/ion/bug820873.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/ion/bug820873.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+
+var lfcode = new Array();
+lfcode.push("3");
+lfcode.push("with(evalcx('')) this.__defineGetter__('x', Function);");
+lfcode.push("gczeal(2)");
+lfcode.push("4");
+lfcode.push("\
+	var log = '';\
+	for (var { m  } = i = 0 ;  ; i++) {\
+		log += x; \
+		if (x === 6)\
+			a.slow = true; if (i > 1000) break;\
+	}\
+");
+while (true) {
+	var file = lfcode.shift(); if (file == undefined) { break; }
+        loadFile(file)
+}
+function loadFile(lfVarx) {
+	if (!isNaN(lfVarx)) {
+            lfRunTypeId = parseInt(lfVarx);
+        } else {
+            switch (lfRunTypeId) {
+                case 3: function newFunc(x) { new Function(x)(); }; newFunc(lfVarx); break;
+                case 4: eval("(function() { " + lfVarx + " })();"); break;
+	}
+    }
+}