diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testBug783540.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testBug783540.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,5 @@
+gczeal(2, 2)
+var stringA = "abcdef";
+var stringB = "ghijk";
+var stringC = "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz";
+(stringA + stringB + stringC).replace('abc', 'AA')