[gedit/gnome-3-2] Be more robust when closing the dialog

[Paolo Borelli <pborelli src gnome org>]

commit 11fbe0fe146fb60d5f3974fc67fe598361cd02ea
Author: Paolo Borelli <pborelli gnome org>
Date:   Mon Dec 26 11:46:28 2011 +0100

    Be more robust when closing the dialog
    
    Gtk started to emit cursor-changed when the treeview is destroyed. I am
    not sure if it is a Gtk bug or if it is intentional, but we should check
    for errors returned by the getter function.

 gedit/dialogs/gedit-preferences-dialog.c |   24 ++++++++++++++----------
 1 files changed, 14 insertions(+), 10 deletions(-)
---
diff --git a/gedit/dialogs/gedit-preferences-dialog.c b/gedit/dialogs/gedit-preferences-dialog.c
index 88058ab..2d04b76 100644
--- a/gedit/dialogs/gedit-preferences-dialog.c
+++ b/gedit/dialogs/gedit-preferences-dialog.c
@@ -486,21 +486,25 @@ style_scheme_changed (GtkWidget              *treeview,
 		      GeditPreferencesDialog *dlg)
 {
 	GtkTreePath *path;
-	GtkTreeIter iter;
-	gchar *id;
 
 	gtk_tree_view_get_cursor (GTK_TREE_VIEW (dlg->priv->schemes_treeview), &path, NULL);
-	gtk_tree_model_get_iter (GTK_TREE_MODEL (dlg->priv->schemes_treeview_model),
-				 &iter, path);
-	gtk_tree_path_free (path);
-	gtk_tree_model_get (GTK_TREE_MODEL (dlg->priv->schemes_treeview_model),
-			    &iter, ID_COLUMN, &id, -1);
+	if (path != NULL)
+	{
+		GtkTreeIter iter;
+		gchar *id;
 
-	g_settings_set_string (dlg->priv->editor, GEDIT_SETTINGS_SCHEME, id);
+		gtk_tree_model_get_iter (GTK_TREE_MODEL (dlg->priv->schemes_treeview_model),
+					 &iter, path);
+		gtk_tree_path_free (path);
+		gtk_tree_model_get (GTK_TREE_MODEL (dlg->priv->schemes_treeview_model),
+				    &iter, ID_COLUMN, &id, -1);
 
-	set_buttons_sensisitivity_according_to_scheme (dlg, id);
+		g_settings_set_string (dlg->priv->editor, GEDIT_SETTINGS_SCHEME, id);
 
-	g_free (id);
+		set_buttons_sensisitivity_according_to_scheme (dlg, id);
+
+		g_free (id);
+	}
 }
 
 static const gchar *