diff --git a/content/xbl/src/nsXBLBinding.cpp b/content/xbl/src/nsXBLBinding.cpp
index 89a19d58364..760c6a107c8 100644
--- a/content/xbl/src/nsXBLBinding.cpp
+++ b/content/xbl/src/nsXBLBinding.cpp
@@ -1084,6 +1084,8 @@ nsXBLBinding::InstallProperties()
     rv = global->GetContext(getter_AddRefs(context));
     if (NS_FAILED(rv)) return rv;
 
+    if (!context) return NS_OK;
+
     // Init our class and insert it into the prototype chain.
     nsAutoString className;
     nsCAutoString classStr; 
@@ -1779,6 +1781,8 @@ nsXBLBinding::AddScriptEventListener(nsIContent* aElement, nsIAtom* aName,
   rv = global->GetContext(getter_AddRefs(context));
   if (NS_FAILED(rv)) return rv;
 
+  if (!context) return NS_OK;
+
   nsCOMPtr<nsIEventListenerManager> manager;
   rv = receiver->GetListenerManager(getter_AddRefs(manager));
   if (NS_FAILED(rv)) return rv;
diff --git a/content/xbl/src/nsXBLPrototypeHandler.cpp b/content/xbl/src/nsXBLPrototypeHandler.cpp
index 7e6b3a1cf38..502c8a095ba 100644
--- a/content/xbl/src/nsXBLPrototypeHandler.cpp
+++ b/content/xbl/src/nsXBLPrototypeHandler.cpp
@@ -384,6 +384,7 @@ nsXBLPrototypeHandler::ExecuteHandler(nsIDOMEventReceiver* aReceiver,
 
   nsCOMPtr<nsIScriptContext> boundContext;
   boundGlobal->GetContext(getter_AddRefs(boundContext));
+  if (!boundContext) return NS_OK;
 
   JSObject* scriptObject = nsnull;
 
diff --git a/content/xul/content/src/nsXULElement.cpp b/content/xul/content/src/nsXULElement.cpp
index a1d281e6012..cc10c9ef446 100644
--- a/content/xul/content/src/nsXULElement.cpp
+++ b/content/xul/content/src/nsXULElement.cpp
@@ -1857,6 +1857,8 @@ nsXULElement::AddScriptEventListener(nsIAtom* aName,
 
         rv = global->GetContext(getter_AddRefs(context));
         if (NS_FAILED(rv)) return rv;
+
+        if (!context) return NS_OK;
     }
 
     nsCOMPtr<nsIContent> root;
diff --git a/content/xul/content/src/nsXULPopupListener.cpp b/content/xul/content/src/nsXULPopupListener.cpp
index 1f95ff8e880..30f6493c297 100644
--- a/content/xul/content/src/nsXULPopupListener.cpp
+++ b/content/xul/content/src/nsXULPopupListener.cpp
@@ -813,7 +813,7 @@ XULPopupListenerImpl::LaunchPopup(PRInt32 aClientX, PRInt32 aClientY)
   nsCOMPtr<nsIScriptGlobalObject> global;
   document->GetScriptGlobalObject(getter_AddRefs(global));
   if (global) {
-    if (NS_OK == global->GetContext(getter_AddRefs(context))) {
+    if ((NS_OK == global->GetContext(getter_AddRefs(context))) && context) {
       // Get the DOM window
       nsCOMPtr<nsIDOMWindowInternal> domWindow = do_QueryInterface(global);
       if (domWindow != nsnull) {
diff --git a/content/xul/document/src/nsXULDocument.cpp b/content/xul/document/src/nsXULDocument.cpp
index 3d75f5521f0..55f9c683399 100644
--- a/content/xul/document/src/nsXULDocument.cpp
+++ b/content/xul/document/src/nsXULDocument.cpp
@@ -5173,6 +5173,8 @@ nsXULDocument::ExecuteScript(JSObject* aScriptObject)
     rv = mScriptGlobalObject->GetContext(getter_AddRefs(context));
     if (NS_FAILED(rv)) return rv;
 
+    if (! context) return NS_ERROR_UNEXPECTED;
+
     rv = context->ExecuteScript(aScriptObject, nsnull, nsnull, nsnull);
     return rv;
 }
diff --git a/dom/src/jsurl/nsJSProtocolHandler.cpp b/dom/src/jsurl/nsJSProtocolHandler.cpp
index 20152b72339..75b6073d199 100644
--- a/dom/src/jsurl/nsJSProtocolHandler.cpp
+++ b/dom/src/jsurl/nsJSProtocolHandler.cpp
@@ -155,6 +155,8 @@ nsresult nsJSThunk::EvaluateScript()
     if (NS_FAILED(rv))
         return rv;
 
+    if (!scriptContext) return NS_ERROR_FAILURE;
+
     // Get principal of code for execution
     nsCOMPtr<nsISupports> owner;
     rv = mChannel->GetOwner(getter_AddRefs(owner));
diff --git a/modules/plugin/base/src/nsPluginInstancePeer.cpp b/modules/plugin/base/src/nsPluginInstancePeer.cpp
index fd229e6edea..2f8c947ecb3 100644
--- a/modules/plugin/base/src/nsPluginInstancePeer.cpp
+++ b/modules/plugin/base/src/nsPluginInstancePeer.cpp
@@ -882,8 +882,10 @@ NS_IMETHODIMP nsPluginInstancePeerImpl::GetJSContext(JSContext* *outContext)
       nsCOMPtr<nsIScriptContext> context;
 
       if (global->GetContext(getter_AddRefs(context)) == NS_OK) {
-        *outContext = (JSContext*) context->GetNativeContext();
-        rv = NS_OK;
+        if (context) {
+            *outContext = (JSContext*) context->GetNativeContext();
+            rv = NS_OK;
+        }
       }
     }
   }
diff --git a/modules/plugin/nglsrc/nsPluginInstancePeer.cpp b/modules/plugin/nglsrc/nsPluginInstancePeer.cpp
index fd229e6edea..2f8c947ecb3 100644
--- a/modules/plugin/nglsrc/nsPluginInstancePeer.cpp
+++ b/modules/plugin/nglsrc/nsPluginInstancePeer.cpp
@@ -882,8 +882,10 @@ NS_IMETHODIMP nsPluginInstancePeerImpl::GetJSContext(JSContext* *outContext)
       nsCOMPtr<nsIScriptContext> context;
 
       if (global->GetContext(getter_AddRefs(context)) == NS_OK) {
-        *outContext = (JSContext*) context->GetNativeContext();
-        rv = NS_OK;
+        if (context) {
+            *outContext = (JSContext*) context->GetNativeContext();
+            rv = NS_OK;
+        }
       }
     }
   }
diff --git a/webshell/tests/viewer/nsViewerApp.cpp b/webshell/tests/viewer/nsViewerApp.cpp
index c26237b9633..9bcaf7f5aed 100644
--- a/webshell/tests/viewer/nsViewerApp.cpp
+++ b/webshell/tests/viewer/nsViewerApp.cpp
@@ -1593,7 +1593,7 @@ static void ShowConsole(nsBrowserWindow* aWindow)
       nsIScriptContext *context = nsnull;
       nsCOMPtr<nsIScriptGlobalObject> scriptGlobal(do_GetInterface(aWindow->mDocShell));
       if (scriptGlobal) {       
-        if (NS_OK == scriptGlobal->GetContext(&context)) {
+        if ((NS_OK == scriptGlobal->GetContext(&context)) && context) {
 
           // create the console
           gConsole = JSConsole::CreateConsole();