diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_global-method-override.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_global-method-override.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests that scripts that override properties of the global object, like
+ * toString don't break the debugger. The test page used to cause the debugger
+ * to throw when trying to attach to the thread actor.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_global-method-override.html";
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    let gDebugger = aPanel.panelWin;
+    ok(gDebugger, "Should have a debugger available.");
+    is(gDebugger.gThreadClient.state, "attached", "Debugger should be attached.");
+
+    closeDebuggerAndFinish(aPanel);
+  });
+}