Solidify Entry discarding logic (NavigationHandle keeps its ID)

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 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/browser/frame_host/render_frame_host_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/containers/hash_tables.h"
@@ skipping 987 matching lines @@
           validated_params.page_state)) {
     bad_message::ReceivedBadMessage(
         GetProcess(), bad_message::RFH_CAN_ACCESS_FILES_OF_PAGE_STATE);
     return;
   }
 
   // If the URL does not match what the NavigationHandle expects, treat the
   // commit as a new navigation. This can happen if an ongoing slow
   // same-process navigation is interrupted by a synchronous renderer-initiated
   // navigation.
+  // TODO(csharrison): Data navigations with base URLs get reset here, because

[Charlie Reis, 2016/02/19 18:00:11]

Mention LoadDataWithBaseURL explicitly here.

[Charlie Harrison, 2016/02/22 14:50:42]

Done.

+  // the NavigationHandle tracks the base URL but the validated_params.url track

[Charlie Reis, 2016/02/19 18:00:11]

nit: tracks the data

[Charlie Harrison, 2016/02/22 14:50:42]

Done.

+  // the data. The trick of saving the old entry ids for these navigations
+  // should go away when this is properly handled.

[Charlie Reis, 2016/02/19 18:00:11]

Let's add a bug number for this work, since it's going to require a
discussion/investigation of its own.

[Charlie Harrison, 2016/02/22 14:50:42]

Done.

+  int entry_id_for_data_nav = 0;
   if (navigation_handle_ &&
-      navigation_handle_->GetURL() != validated_params.url) {
+      (navigation_handle_->GetURL() != validated_params.url)) {
+    if (navigation_handle_->GetURL() == validated_params.base_url)

[Charlie Reis, 2016/02/19 18:00:11]

This base_url gets used for other cases as well, according to
FrameNavigateParams.  I'm a bit concerned that this could make us propagate the
entry ID for a non-matching renderer-initiated synchronous nav (e.g.,
pushState), if it can have a base_url that matches the pending NavigationHandle.

Is there any way to check something that's specific to LoadDataWithBaseURL?  I
see GetBaseURLForDataURL on NavigationEntry, though it's not great to look at
NavigationEntries directly here (and I'm not 100% sure if it will always exist).
 NavigationHandle doesn't seem to track it yet, though, so maybe the entry would
do.

+      entry_id_for_data_nav = navigation_handle_->pending_nav_entry_id();
     navigation_handle_.reset();
   }
 
   // Synchronous renderer-initiated navigations will send a
   // DidCommitProvisionalLoad IPC without a prior DidStartProvisionalLoad
   // message.
   if (!navigation_handle_) {
+    // There is no pending NavigationEntry in these cases, so pass 0 as the
+    // nav_id. If the previous handle was a prematurely aborted data nav, then

[Charlie Reis, 2016/02/19 18:00:11]

Note: It's important to distinguish between a data URL navigation (which is
commonplace and doesn't break any rules) and LoadDataWithBaseURL (which is
Android Webview specific and causes problems like this).

[Charlie Harrison, 2016/02/22 14:50:42]

Fixed the wording.

+    // propagate the entry id.
     navigation_handle_ =
         NavigationHandleImpl::Create(validated_params.url, frame_tree_node_,
                                      true,   // is_synchronous
                                      false,  // is_srcdoc
-                                     base::TimeTicks::Now());
+                                     base::TimeTicks::Now(),
+                                     entry_id_for_data_nav);
   }
 
   accessibility_reset_count_ = 0;
   frame_tree_node()->navigator()->DidNavigate(this, validated_params);
 
   // For a top-level frame, there are potential security concerns associated
   // with displaying graphics from a previously loaded page after the URL in
   // the omnibar has been changed. It is unappealing to clear the page
   // immediately, but if the renderer is taking a long time to issue any
   // compositor output (possibly because of script deliberately creating this
@@ skipping 1533 matching lines @@
   *dst = src;
 
   if (src.routing_id != -1)
     dst->tree_id = RoutingIDToAXTreeID(src.routing_id);
 
   if (src.parent_routing_id != -1)
     dst->parent_tree_id = RoutingIDToAXTreeID(src.parent_routing_id);
 }
 
 }  // namespace content