A stab at fixing a crashing bug and a bandaid to prevent the crash if that stab is in the wrong p...

webkit/appcache/appcache_request_handler.cc

 // Copyright (c) 2011 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 "webkit/appcache/appcache_request_handler.h"
 
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_job.h"
 #include "webkit/appcache/appcache.h"
 #include "webkit/appcache/appcache_url_request_job.h"
@@ skipping 40 matching lines @@
   // earlier call thru this method. To send the request thru
   // to the network involves restarting the request altogether,
   // which will call thru to our interception layer again.
   // This time thru, we return NULL so the request hits the wire.
   if (job_) {
     DCHECK(job_->is_delivering_network_response() ||
            job_->cache_entry_not_found());
     if (job_->cache_entry_not_found())
       cache_entry_not_found_ = true;
     job_ = NULL;
+    storage()->CancelDelegateCallbacks(this);
     return NULL;
   }
 
   // Clear out our 'found' fields since we're starting a request for a
   // new resource, any values in those fields are no longer valid.
   found_entry_ = AppCacheEntry();
   found_fallback_entry_ = AppCacheEntry();
   found_cache_id_ = kNoCacheId;
   found_manifest_url_ = GURL();
   found_network_namespace_ = false;
@@ skipping 140 matching lines @@
   job_ = new AppCacheURLRequestJob(request, storage());
   storage()->FindResponseForMainRequest(
       request->url(), preferred_manifest_url, this);
 }
 
 void AppCacheRequestHandler::OnMainResponseFound(
     const GURL& url, const AppCacheEntry& entry,
     const GURL& fallback_url, const AppCacheEntry& fallback_entry,
     int64 cache_id, const GURL& manifest_url,
     bool was_blocked_by_policy) {
+  DCHECK(job_);
   DCHECK(host_);
   DCHECK(is_main_resource());
   DCHECK(!entry.IsForeign());
   DCHECK(!fallback_entry.IsForeign());
   DCHECK(!(entry.has_response_id() && fallback_entry.has_response_id()));
 
+  if (!job_)
+    return;
+
   if (ResourceType::IsFrame(resource_type_)) {
     if (was_blocked_by_policy)
       host_->NotifyMainResourceBlocked(manifest_url);
 
     if (cache_id != kNoCacheId) {
       // AppCacheHost loads and holds a reference to the main resource cache
       // for two reasons, firstly to preload the cache into the working set
       // in advance of subresource loads happening, secondly to prevent the
       // AppCache from falling out of the working set on frame navigations.
       host_->LoadMainResourceCache(cache_id);
@@ skipping 107 matching lines @@
   if (!host_->associated_cache() ||
       !host_->associated_cache()->is_complete()) {
     DeliverNetworkResponse();
     return;
   }
 
   ContinueMaybeLoadSubResource();
 }
 
 }  // namespace appcache