Evil wallpaper hack to hide a crash when going back from an interstitial and then renavigating very quickly.

BUG=2855
Review URL: http://codereview.chromium.org/9330

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@4608 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 0 deletions

diff --git a/chrome/browser/navigation_controller.cc b/chrome/browser/navigation_controller.cc
index 77d5269..cc05bc7d 100644
--- a/chrome/browser/navigation_controller.cc
+++ b/chrome/browser/navigation_controller.cc
@@ -929,6 +929,23 @@ void NavigationController::DiscardNonCommittedEntries() {
   NavigationEntry* last_entry = GetLastCommittedEntry();
   if (last_entry && last_entry->tab_type() != active_contents_->type()) {
     TabContents* from_contents = active_contents_;
+    if (from_contents->type() == active_contents_->type()) {
+      // EVIL HACK ALERT! This condition is a wallpaper patch around bug
+      // http://code.google.com/p/chromium/issues/detail?id=2855
+      // See the bug for more, but the short answer is that an old render view
+      // host's "cancel" message will get received by a newer one that happens
+      // to be navigated to the same URL, which will trigger improperly
+      // discarding the pending entry. This will in turn trigger tab contents
+      // collection and other bad things.
+      //
+      // This early return doesn't fix the problem at all, but does prevent the
+
+      // immediate crash. There are very likely to be problems as a result of
+      // the confused state that this generates, so the underlying bug really
+      // needs to be fixed!
+      return;
+    }
+
     from_contents->set_is_active(false);
 
     // Switch back to the previous tab contents.