[gtk+] gtktreemodelfilter: child levels of the root level must remain cached

[Kristian Rietveld <kristian src gnome org>]

commit 022327c408e1439246ea688380288e0491172a9c
Author: Kristian Rietveld <kris gtk org>
Date:   Wed Sep 7 22:11:37 2011 +0200

    gtktreemodelfilter: child levels of the root level must remain cached
    
    This is due to the special handling for filter functions that depend
    on child level state.  If the parent level of a level is the root level,
    the level cannot be removed from the cache.  Any change in this level
    can cause its parent in the root level to become visible again.

 gtk/gtktreemodelfilter.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtktreemodelfilter.c b/gtk/gtktreemodelfilter.c
index d3560ed..bf954e1 100644
--- a/gtk/gtktreemodelfilter.c
+++ b/gtk/gtktreemodelfilter.c
@@ -1302,9 +1302,13 @@ gtk_tree_model_filter_clear_cache_helper (GtkTreeModelFilter *filter,
    * free the level if the parent level also has an external ref
    * count of zero.  In that case, changes concerning our parent are
    * not requested.
+   *
+   * The root level is always visible, so an exception holds for levels
+   * with the root level as parent level: these have to remain cached.
    */
   if (level->ext_ref_count == 0 && level != filter->priv->root &&
-      level->parent_level && level->parent_level->ext_ref_count == 0)
+      level->parent_level && level->parent_level != filter->priv->root &&
+      level->parent_level->ext_ref_count == 0)
     {
       gtk_tree_model_filter_free_level (filter, level, TRUE, FALSE);
       return;