PPAPI: Check for NULL before calling WebBindings::evaluate

content/renderer/pepper/pepper_plugin_instance_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/pepper/pepper_plugin_instance_impl.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 2366 matching lines @@
   StringVar* script_string = StringVar::FromPPVar(script);
   if (!script_string) {
     try_catch.SetException("Script param to ExecuteScript must be a string.");
     return PP_MakeUndefined();
   }
   NPString np_script;
   np_script.UTF8Characters = script_string->value().c_str();
   np_script.UTF8Length = script_string->value().length();
 
   // Get the current frame to pass to the evaluate function.
-  WebLocalFrame* frame = container_->element().document().frame();
-  if (!frame) {
+  WebLocalFrame* frame = NULL;
+  if (container_)
+    frame = container_->element().document().frame();
+  if (!frame || !frame->windowObject()) {
     try_catch.SetException("No frame to execute script in.");

[teravest, 2014/07/21 19:38:04]

This error message doesn't seem correct anymore. If frame->windowObject is NULL,
there is still a frame to execute the script in; there just isn't a
corresponding NPObject.

[dmichael (off chromium), 2014/07/21 19:57:47]

"improved"

     return PP_MakeUndefined();
   }
 
   NPVariant result;
   bool ok = false;
   if (IsProcessingUserGesture()) {
     blink::WebScopedUserGesture user_gesture(CurrentUserGestureToken());
     ok =
         WebBindings::evaluate(NULL, frame->windowObject(), &np_script, &result);
   } else {
@@ skipping 906 matching lines @@
     // Running out-of-process. Initiate an IPC call to notify the plugin
     // process.
     ppapi::proxy::HostDispatcher* dispatcher =
         ppapi::proxy::HostDispatcher::GetForInstance(pp_instance());
     dispatcher->Send(new PpapiMsg_PPPInstance_HandleDocumentLoad(
         ppapi::API_ID_PPP_INSTANCE, pp_instance(), pending_host_id, data));
   }
 }
 
 }  // namespace content