Fixing a bug with interstitial pages triggered with malware....

chrome/browser/safe_browsing/safe_browsing_blocking_page.cc

 // Copyright (c) 2006-2008 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.
 //
 // Implementation of the SafeBrowsingBlockingPage class.
 
 #include "chrome/browser/safe_browsing/safe_browsing_blocking_page.h"
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
@@ skipping 443 matching lines @@
   return Singleton<UnsafeResourceMap>::get();
 }
 
 // static
 void SafeBrowsingBlockingPage::ShowBlockingPage(
     SafeBrowsingService* sb_service,
     const SafeBrowsingService::UnsafeResource& unsafe_resource) {
   TabContents* tab_contents = tab_util::GetTabContentsByID(
       unsafe_resource.render_process_host_id, unsafe_resource.render_view_id);
 
-  if (!InterstitialPage::GetInterstitialPage(tab_contents)) {
+  InterstitialPage* interstitial =
+      InterstitialPage::GetInterstitialPage(tab_contents);
+  if (interstitial &&
+      unsafe_resource.resource_type == ResourceType::MAIN_FRAME) {
+    // There is already an interstitial showing and we are about to display a
+    // new one for the main frame. Just hide the current one, it is now
+    // irrelevent
+    interstitial->DontProceed();
+    interstitial = NULL;
+  }
+
+  if (!interstitial) {
     // There are no interstitial currently showing in that tab, go ahead and
     // show this interstitial.
     std::vector<SafeBrowsingService::UnsafeResource> resources;
     resources.push_back(unsafe_resource);
     // Set up the factory if this has not been done already (tests do that
     // before this method is called).
     if (!factory_)
       factory_ = Singleton<SafeBrowsingBlockingPageFactoryImpl>::get();
     SafeBrowsingBlockingPage* blocking_page =
         factory_->CreateSafeBrowsingPage(sb_service, tab_contents, resources);
     blocking_page->Show();
     return;
   }
 
-  // Let's queue the interstitial.
-  // Note we only expect resources from the page at this point.
-  DCHECK(unsafe_resource.resource_type != ResourceType::MAIN_FRAME);
+  // This is an interstitial for a page's resource, let's queue it.
   UnsafeResourceMap* unsafe_resource_map = GetUnsafeResourcesMap();
   (*unsafe_resource_map)[tab_contents].push_back(unsafe_resource);
 }
 
 // static
 bool SafeBrowsingBlockingPage::IsMainPage(
     const UnsafeResourceList& unsafe_resources) {
   return unsafe_resources.size() == 1 &&
          unsafe_resources[0].resource_type == ResourceType::MAIN_FRAME;
 }