diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/RegExp/empty-lookahead.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/RegExp/empty-lookahead.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+//bug 473941
+var regexp;
+
+regexp = /(?=)/;
+assertEq(regexp.test('test'), true);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);