91365. r=dougt, sr=hyatt. nsIScriptGlobalObject->GetContext() can legitimately return NS_OK *and* a nsnull outparam. Various callsites were not respecting the nsnull out param and this patch gracefully handles those cases.

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;

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;
 

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;

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) {

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;
 }

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));

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();
+        if (context) {
-        rv = NS_OK;
+            *outContext = (JSContext*) context->GetNativeContext();
+            rv = NS_OK;
+        }
       }
     }
   }

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();
+        if (context) {
-        rv = NS_OK;
+            *outContext = (JSContext*) context->GetNativeContext();
+            rv = NS_OK;
+        }
       }
     }
   }

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();