diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-07.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Debugger-onNewGlobalObject-07.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+// One Debugger's onNewGlobalObject handler can disable other Debuggers.
+
+var dbg1 = new Debugger;
+var dbg2 = new Debugger;
+var dbg3 = new Debugger;
+var log;
+var hit;
+
+function handler(global) {
+  hit++;
+  log += hit;
+  if (hit == 2)
+    dbg1.enabled = dbg2.enabled = dbg3.enabled = false;
+};
+
+log = '';
+hit = 0;
+dbg1.onNewGlobalObject = dbg2.onNewGlobalObject = dbg3.onNewGlobalObject = handler;
+newGlobal();
+assertEq(log, '12');