diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/saved-stacks/same-stack.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/saved-stacks/same-stack.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,12 @@
+// Test that the same saved stack is only ever allocated once.
+
+const stacks = [];
+
+for (let i = 0; i < 10; i++) {
+  stacks.push(saveStack());
+}
+
+const s = stacks.pop();
+for (let stack of stacks) {
+  assertEq(s, stack);
+}