diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testBug705423.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testBug705423.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,19 @@
+gczeal(1);
+
+var g = newGlobal();
+
+g.eval("\
+var f = function(x) { \
+    arg = arguments; \
+    fun = function() { return x }; \
+} \
+");
+
+g.f(3);
+g.f = null;
+assertEq(g.fun(), 3);
+assertEq(g.arg[0], 3);
+gc();
+g.arg[0] = 9;
+assertEq(g.fun(), 9);
+assertEq(g.arg[0], 9);