Index: gtk/gtktreeview.c
===================================================================
--- gtk/gtktreeview.c	(Revision 20719)
+++ gtk/gtktreeview.c	(Arbeitskopie)
@@ -777,7 +777,8 @@ gtk_tree_view_class_init (GtkTreeViewCla
 #define _TREE_VIEW_EXPANDER_SIZE 12
 #define _TREE_VIEW_VERTICAL_SEPARATOR 2
 #define _TREE_VIEW_HORIZONTAL_SEPARATOR 2
-    
+#define _TREE_VIEW_SEPARATOR_HEIGHT 2
+
   gtk_widget_class_install_style_property (widget_class,
 					   g_param_spec_int ("expander-size",
 							     P_("Expander Size"),
@@ -868,6 +869,15 @@ gtk_tree_view_class_init (GtkTreeViewCla
 								"\1\1",
 								GTK_PARAM_READABLE));
 
+  gtk_widget_class_install_style_property (widget_class,
+                                           g_param_spec_int ("separator-height",
+                                                             P_("Separator Height"),
+                                                             P_("Height of separator rows"),
+                                                             0,
+                                                             G_MAXINT,
+                                                             _TREE_VIEW_SEPARATOR_HEIGHT,
+                                                             GTK_PARAM_READABLE));
+
   /* Signals */
   widget_class->set_scroll_adjustments_signal =
     g_signal_new (I_("set_scroll_adjustments"),
@@ -5523,6 +5533,7 @@ validate_row (GtkTreeView *tree_view,
   gboolean draw_vgrid_lines, draw_hgrid_lines;
   gint focus_pad;
   gint grid_line_width;
+  gint separator_height;
 
   /* double check the row needs validating */
   if (! GTK_RBNODE_FLAG_SET (node, GTK_RBNODE_INVALID) &&
@@ -5537,6 +5548,7 @@ validate_row (GtkTreeView *tree_view,
 			"horizontal-separator", &horizontal_separator,
 			"vertical-separator", &vertical_separator,
 			"grid-line-width", &grid_line_width,
+                        "separator-height", &separator_height,
 			NULL);
   
   draw_vgrid_lines =
@@ -5583,7 +5595,7 @@ validate_row (GtkTreeView *tree_view,
 	  height = MAX (height, tree_view->priv->expander_size);
 	}
       else
-	height = 2 + 2 * focus_pad;
+        height = separator_height + 2 * focus_pad;
 
       if (gtk_tree_view_is_expander_column (tree_view, column))
         {
