diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testBug621202.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testBug621202.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,16 @@
+const MAX = 10000;
+
+var arr = [];
+var str = "";
+for (var i = 0; i < MAX; ++i) {
+    /x/.test(str);
+    str = str + 'xxxxxxxxxxxxxx';
+    arr.push(str);
+}
+
+arr.length = Math.floor(MAX/3);
+gc();
+
+for (var i = 0; i < MAX; ++i) {
+    /x/.test(arr[i]);
+}