Make the Go Back navigation work even when redirection is involved....

chrome/browser/tab_contents/navigation_controller.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.
 
 #include "chrome/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 587 matching lines @@
     new_entry = new NavigationEntry;
   }
 
   new_entry->set_url(params.url);
   new_entry->set_referrer(params.referrer);
   new_entry->set_page_id(params.page_id);
   new_entry->set_transition_type(params.transition);
   new_entry->set_site_instance(tab_contents_->GetSiteInstance());
   new_entry->set_has_post_data(params.is_post);
 
-  InsertEntry(new_entry);
+  if (PageTransition::IsRedirect(new_entry->transition_type())) {
+    // The current entry is a redirection source. It needs to be replaced with
+    // the new entry to avoid unwanted redirections in navigating backward /
+    // forward.
+    ReplaceCurrentEntry(new_entry);
+  } else {
+    InsertEntry(new_entry);
+  }
 }
 
 void NavigationController::RendererDidNavigateToExistingPage(
     const ViewHostMsg_FrameNavigate_Params& params) {
   // We should only get here for main frame navigations.
   DCHECK(PageTransition::IsMainFrame(params.transition));
 
   // This is a back/forward navigation. The existing page for the ID is
   // guaranteed to exist by ClassifyNavigation, and we just need to update it
   // with new information from the renderer.
@@ skipping 182 matching lines @@
 
   // If there was a transient entry, invalidate everything so the new active
   // entry state is shown.
   if (transient) {
     tab_contents_->NotifyNavigationStateChanged(
         TabContents::INVALIDATE_EVERYTHING);
   }
 }
 
 void NavigationController::InsertEntry(NavigationEntry* entry) {
+  InsertOrReplaceEntry(entry, false);
+}
+
+void NavigationController::ReplaceCurrentEntry(NavigationEntry* entry) {
+  InsertOrReplaceEntry(entry, true);
+}
+
+void NavigationController::InsertOrReplaceEntry(

[brettw, 2009/04/24 20:57:59]

When all the args fit, we usually like to wrap the args like this:

...laceEntry(NavigationEntry* entry,
             bool replace) {

+      NavigationEntry* entry, bool replace) {
   DCHECK(entry->transition_type() != PageTransition::AUTO_SUBFRAME);
 
   // Copy the pending entry's unique ID to the committed entry.
   // I don't know if pending_entry_index_ can be other than -1 here.
   const NavigationEntry* const pending_entry = (pending_entry_index_ == -1) ?
       pending_entry_ : entries_[pending_entry_index_].get();
   if (pending_entry)
     entry->set_unique_id(pending_entry->unique_id());
 
   DiscardNonCommittedEntriesInternal();
 
   int current_size = static_cast<int>(entries_.size());
 
-  // Prune any entries which are in front of the current entry.
   if (current_size > 0) {
+    // Prune any entries which are in front of the current entry.
+    // Also prune the current entry if we are to replace the current entry.
+    int prune_up_to = replace ? last_committed_entry_index_ - 1
+                              : last_committed_entry_index_;
     int num_pruned = 0;
-    while (last_committed_entry_index_ < (current_size - 1)) {
+    while (prune_up_to < (current_size - 1)) {
       num_pruned++;
       entries_.pop_back();
       current_size--;
     }
     if (num_pruned > 0)  // Only notify if we did prune something.
       NotifyPrunedEntries(this, false, num_pruned);
   }
 
   if (entries_.size() >= max_entry_count_) {
     RemoveEntryAtIndex(0, GURL());
@@ skipping 111 matching lines @@
       return i;
   }
   return -1;
 }
 
 NavigationEntry* NavigationController::GetTransientEntry() const {
   if (transient_entry_index_ == -1)
     return NULL;
   return entries_[transient_entry_index_].get();
 }