[gtk+] Revert "treeview: Remove unneeded checks"

[Matthias Clasen <matthiasc src gnome org>]

commit 210453b79ec84beb212249592a403a0332e81caf
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Jun 1 10:09:52 2014 -0400

    Revert "treeview: Remove unneeded checks"
    
    This reverts commit a158a2aa48c8023f99963642cc2657bff207b82d.
    
    The commit conflicts with a later revert, so move it out of the way.

 gtk/gtktreeview.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtktreeview.c b/gtk/gtktreeview.c
index 4862535..868af44 100644
--- a/gtk/gtktreeview.c
+++ b/gtk/gtktreeview.c
@@ -2591,8 +2591,10 @@ gtk_tree_view_get_preferred_width (GtkWidget *widget,
        tree_view->priv->n_expand_columns++;
     }
 
-  *minimum = tree_view->priv->minimum_width;
-  *natural = tree_view->priv->natural_width;
+  if (minimum != NULL)
+    *minimum = tree_view->priv->minimum_width;
+  if (natural != NULL)
+    *natural = tree_view->priv->natural_width;
 }
 
 static void
@@ -2607,8 +2609,10 @@ gtk_tree_view_get_preferred_height (GtkWidget *widget,
 
   height = gtk_tree_view_get_height (tree_view) + gtk_tree_view_get_effective_header_height (tree_view);
 
-  *minimum = height;
-  *natural = height;
+  if (minimum != NULL)
+    *minimum = height;
+  if (natural != NULL)
+    *natural = height;
 }
 
 static void