diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug970643.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug970643.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+// |jit-test| exitstatus: 6;
+
+setJitCompilerOption("baseline.usecount.trigger", 1);
+setJitCompilerOption("ion.usecount.trigger", 2);
+
+// The timepout function is made to trigger the interruption callback. The
+// interruption callback will protect the code while a GC might be
+// marking/updating pointers in it.
+var x = 0;
+function interrupt_gc() {
+  if (x++ >= 20)
+    return;
+  timeout(0.1, interrupt_gc);
+  while(x < 20)
+    gc();
+}
+
+interrupt_gc();