diff --git a/mozilla/content/events/src/nsEventListenerManager.cpp b/mozilla/content/events/src/nsEventListenerManager.cpp
index 60a27e0a5b6..dd5e5d3a0ae 100644
--- a/mozilla/content/events/src/nsEventListenerManager.cpp
+++ b/mozilla/content/events/src/nsEventListenerManager.cpp
@@ -816,6 +816,7 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
                                           handler);
         if (rv == NS_ERROR_ILLEGAL_VALUE) {
           NS_WARNING("Probably a syntax error in the event handler!");
+          context->ReportPendingException();
           return NS_SUCCESS_LOSS_OF_INSIGNIFICANT_DATA;
         }
         NS_ENSURE_SUCCESS(rv, rv);
diff --git a/mozilla/dom/public/nsIScriptContext.h b/mozilla/dom/public/nsIScriptContext.h
index b34252ee937..84fd98a4d53 100644
--- a/mozilla/dom/public/nsIScriptContext.h
+++ b/mozilla/dom/public/nsIScriptContext.h
@@ -57,9 +57,9 @@ class nsScriptObjectHolder;
 typedef void (*nsScriptTerminationFunc)(nsISupports* aRef);
 
 #define NS_ISCRIPTCONTEXT_IID \
-{ /* {09316a0e-8d05-4d26-9efd-8f907a7c79d2} */ \
-  0x09316a0e, 0x8d05, 0x4d26, \
- { 0x9e, 0xfd, 0x8f, 0x90, 0x7a, 0x7c, 0x79, 0xd2 } }
+{ /* {e7b9871d-3adc-4bf7-850d-7fb9554886bf} */ \
+  0xe7b9871d, 0x3adc, 0x4bf7, \
+ { 0x85, 0x0d, 0x7f, 0xb9, 0x55, 0x48, 0x86, 0xbf } }
 
 /* This MUST match JSVERSION_DEFAULT.  This version stuff if we don't
    know what language we have is a little silly... */
@@ -451,6 +451,9 @@ public:
    */
   virtual nsresult DropScriptObject(void *object) = 0;
   virtual nsresult HoldScriptObject(void *object) = 0;
+
+  /* Report a pending exception if there is one on the native context */
+  virtual void ReportPendingException() = 0;
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsIScriptContext, NS_ISCRIPTCONTEXT_IID)
diff --git a/mozilla/dom/src/base/nsJSEnvironment.cpp b/mozilla/dom/src/base/nsJSEnvironment.cpp
index 3b96305db97..68c9a6236d0 100644
--- a/mozilla/dom/src/base/nsJSEnvironment.cpp
+++ b/mozilla/dom/src/base/nsJSEnvironment.cpp
@@ -3549,6 +3549,14 @@ nsJSContext::DropScriptObject(void* aScriptObject)
   return NS_OK;
 }
 
+void
+nsJSContext::ReportPendingException()
+{
+  if (mIsInitialized && ::JS_IsExceptionPending(mContext)) {
+    ::JS_ReportPendingException(mContext);
+  }
+}
+
 /**********************************************************************
  * nsJSRuntime implementation
  *********************************************************************/
diff --git a/mozilla/dom/src/base/nsJSEnvironment.h b/mozilla/dom/src/base/nsJSEnvironment.h
index 1b05adce2a4..dec747d9f9b 100644
--- a/mozilla/dom/src/base/nsJSEnvironment.h
+++ b/mozilla/dom/src/base/nsJSEnvironment.h
@@ -166,6 +166,8 @@ public:
   virtual nsresult DropScriptObject(void *object);
   virtual nsresult HoldScriptObject(void *object);
 
+  virtual void ReportPendingException();
+
   NS_DECL_NSIXPCSCRIPTNOTIFY
 
   NS_DECL_NSITIMERCALLBACK
diff --git a/mozilla/extensions/python/dom/src/nsPyContext.cpp b/mozilla/extensions/python/dom/src/nsPyContext.cpp
index 54df062a9da..0def7c34f48 100644
--- a/mozilla/extensions/python/dom/src/nsPyContext.cpp
+++ b/mozilla/extensions/python/dom/src/nsPyContext.cpp
@@ -933,3 +933,9 @@ nsPythonContext::HoldScriptObject(void *object)
   }
   return NS_OK;
 }
+
+void
+nsPythonContext::ReportPendingException()
+{
+  // Not sure there's anything to do here
+}
diff --git a/mozilla/extensions/python/dom/src/nsPyContext.h b/mozilla/extensions/python/dom/src/nsPyContext.h
index e576b0042bb..5fb60ac37cd 100644
--- a/mozilla/extensions/python/dom/src/nsPyContext.h
+++ b/mozilla/extensions/python/dom/src/nsPyContext.h
@@ -213,6 +213,8 @@ public:
   virtual nsresult HoldScriptObject(void *object);
   virtual nsresult DropScriptObject(void *object);
 
+  virtual void ReportPendingException();
+
   NS_DECL_NSITIMERCALLBACK
   
   PyObject *PyObject_FromInterface(nsISupports *target,