Http cache: Fix DCHECK with POSTs and a disabled cache.

net/http/http_cache_transaction.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 "net/http/http_cache_transaction.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 1201 matching lines @@
       (request_->method == "PUT" || request_->method == "DELETE")) {
     if (NonErrorResponse(new_response->headers->response_code())) {
       int ret = cache_->DoomEntry(cache_key_, NULL);
       DCHECK_EQ(OK, ret);
     }
     cache_->DoneWritingToEntry(entry_, true);
     entry_ = NULL;
     mode_ = NONE;
   }
 
-  if (request_->method == "POST" &&
+  if (!(effective_load_flags_ & LOAD_DISABLE_CACHE) &&

[davidben, 2014/10/23 19:14:43]

Should this be mode_ != NONE or mode_ & WRITE or something of the sort? It looks
like LOAD_DISABLE_CACHE figures into ShouldPassThrough() which then controls
mode_.

[rvargas (doing something else), 2014/10/23 19:36:09]

There are multiple causes for mode_ to change between ShouldPassThrough() and
this point. What this line is saying is "unless the conditions when request was
made indicated that this should not affect the cache at all, we should
invalidate any cached entry at this point"

[davidben, 2014/10/23 19:45:42]

Ohh, I see. This is about invalidating GETs after a successful POST, not
something about a cache entry attached to the current request or so.

Perhaps it's worth a comment above 1222 so it's clearer what this block is
doing?

[rvargas (doing something else), 2014/10/23 20:06:15]

Done.

+      request_->method == "POST" &&
       NonErrorResponse(new_response->headers->response_code())) {
     cache_->DoomMainEntryForUrl(request_->url);
   }
 
   RecordVaryHeaderHistogram(new_response);
   RecordNoStoreHeaderHistogram(request_->load_flags, new_response);
 
   if (new_response_->headers->response_code() == 416 &&
       (request_->method == "GET" || request_->method == "POST")) {
     // If there is an active entry it may be destroyed with this transaction.
@@ skipping 1713 matching lines @@
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   // TODO(vadimt): Remove ScopedProfile below once crbug.com/422516 is fixed.
   tracked_objects::ScopedProfile tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("422516 Transaction::OnIOComplete"));
 
   DoLoop(result);
 }
 
 }  // namespace net