1 files changed, 12 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/bug559912.js b/js/src/jit-test/tests/basic/bug559912.js
new file mode 100644
index 0000000000..8f05ff5a3a
--- /dev/null
+++ b/js/src/jit-test/tests/basic/bug559912.js
@@ -0,0 +1,12 @@
+
+function s(f) { this._m = f; }
+function C() {
+    Object.defineProperty(this, "m", {set: s});
+    this.m = function () {};
+}
+var last = {};
+for (var i = 0; i < 20; i++) {
+  var a = new C;
+  assertEq(a._m === last._m, false);
+  last = a;
+}