diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testBranchingUnstableObject.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testBranchingUnstableObject.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+function testBranchingUnstableObject() {
+  var x = {s: "a"};
+  var t = "";
+  for (var i=0; i < 100; ++i) {
+      if (i == 51)
+      {
+        x.s = 5;
+      }
+      t += x.s;
+  }
+  return t.length;
+}
+assertEq(testBranchingUnstableObject(), 100);