diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/auto-regress/bug686107.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/auto-regress/bug686107.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+// |jit-test| error:TypeError
+
+// Binary: cache/js-dbg-64-d078623f7875-linux
+// Flags: -m -n -a
+//
+
+function testKeyTransitions() {
+  var i, key, result, message;
+  var array = [];
+  for (i = 0; i != 10; i++) {
+    key = (i < 3) ? 'pop' : (/\u009e\u0029/g );
+    array[key](i);
+  }
+}
+testKeyTransitions();