diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/dispatch-02.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/dispatch-02.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+// Disabling a Debugger object causes events to stop being delivered to it
+// immediately, even if we're in the middle of dispatching.
+
+var g = newGlobal();
+var log;
+
+var arr = [];
+for (var i = 0; i < 4; i++) {
+    arr[i] = new Debugger(g);
+    arr[i].num = i;
+    arr[i].onDebuggerStatement = function () {
+        log += this.num;
+        // Disable them all.
+        for (var j = 0; j < arr.length; j++)
+            arr[j].enabled = false;
+    };
+}
+
+log = '';
+g.eval("debugger; debugger;");
+assertEq(log, '0');