Fix classification of a history.back() that interrupts a pending navigation.

content/browser/tab_contents/navigation_controller.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 "content/browser/tab_contents/navigation_controller.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "base/time.h"
@@ skipping 623 matching lines @@
     // All manual subframes would get new IDs and were handled above, so we
     // know this is auto. Since the current page was found in the navigation
     // entry list, we're guaranteed to have a last committed entry.
     DCHECK(GetLastCommittedEntry());
     return NavigationType::AUTO_SUBFRAME;
   }
 
   // Anything below here we know is a main frame navigation.
   if (pending_entry_ &&
       existing_entry != pending_entry_ &&
-      pending_entry_->page_id() == -1) {
+      pending_entry_->page_id() == -1 &&
+      existing_entry == GetLastCommittedEntry()) {
     // In this case, we have a pending entry for a URL but WebCore didn't do a
     // new navigation. This happens when you press enter in the URL bar to
     // reload. We will create a pending entry, but WebKit will convert it to
     // a reload since it's the same page and not create a new entry for it
     // (the user doesn't want to have a new back/forward entry when they do
-    // this). In this case, we want to just ignore the pending entry and go
-    // back to where we were (the "existing entry").
+    // this). If this matches the last committed entry, we want to just ignore
+    // the pending entry and go back to where we were (the "existing entry").
     return NavigationType::SAME_PAGE;
   }
 
   // Any toplevel navigations with the same base (minus the reference fragment)
   // are in-page navigations. We weeded out subframe navigations above. Most of
   // the time this doesn't matter since WebKit doesn't tell us about subframe
   // navigations that don't actually navigate, but it can happen when there is
   // an encoding override (it always sends a navigation request).
   if (AreURLsInPageNavigation(existing_entry->url(), params.url))
     return NavigationType::IN_PAGE;
@@ skipping 547 matching lines @@
   size_t insert_index = 0;
   for (int i = 0; i < max_index; i++) {
     // When cloning a tab, copy all entries except interstitial pages
     if (source.entries_[i].get()->page_type() != INTERSTITIAL_PAGE) {
       entries_.insert(entries_.begin() + insert_index++,
                       linked_ptr<NavigationEntry>(
                           new NavigationEntry(*source.entries_[i])));
     }
   }
 }