diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/ion/regexp-exec.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/ion/regexp-exec.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+// RegExp.exec -> RegExp.test optimization should use the builtin test method.
+function f() {
+    var res = 0;
+    for (var i=0; i<100; i++) {
+        if (/a/.exec("a"))
+            res++;
+    }
+    assertEq(res, 100);
+}
+delete RegExp.prototype.test;
+gc();
+f();
+
+RegExp.prototype.test = function() { assertEq(0, 1); }
+gc();
+f();
+
+Object.defineProperty(RegExp.prototype, "test", {get: function() { assertEq(0, 1); }});
+gc();
+f();