Bug 608993 - Add gtk_widget_style_attach()

As replacement for:
widget->style = gtk_style_attach (widget->style, widget->window);

gtk/gtk.symbols

@@ -5230,6 +5230,7 @@ gtk_widget_show_all
 gtk_widget_show_now
 gtk_widget_size_allocate
 gtk_widget_size_request
+gtk_widget_style_attach
 gtk_widget_style_get G_GNUC_NULL_TERMINATED
 gtk_widget_style_get_property
 gtk_widget_style_get_valist

gtk/gtkwidget.c

@@ -6293,6 +6293,32 @@ gtk_widget_get_parent (GtkWidget *widget)
  * see docs/styles.txt
  *****************************************/
 
+/**
+ * gtk_widget_style_attach:
+ * @widget: a #GtkWidget
+ *
+ * This function attaches the widget's #GtkStyle to the widget's
+ * #GdkWindow. It is a replacement for
+ *
+ * <programlisting>
+ * widget->style = gtk_style_attach (widget->style, widget->window);
+ * </programlisting>
+ *
+ * and should only ever be called in a derived widget's "realize"
+ * implementation which does not chain up to its parent class'
+ * "realize" implementation, because one of the parent classes
+ * (finally #GtkWidget) would attach the style itself.
+ *
+ * Since: 2.20
+ **/
+void
+gtk_widget_style_attach (GtkWidget *widget)
+{
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  widget->style = gtk_style_attach (widget->style, widget->window);
+}
+
 /**
  * gtk_widget_has_rc_style:
  * @widget: a #GtkWidget

gtk/gtkwidget.h

@@ -1063,11 +1063,13 @@ gboolean     gtk_widget_hide_on_delete	(GtkWidget	*widget);
 
 /* Widget styles.
  */
-gboolean    gtk_widget_has_rc_style       (GtkWidget           *widget);
-void	   gtk_widget_set_style		(GtkWidget	*widget,
-					 GtkStyle	*style);
-void	   gtk_widget_ensure_style	(GtkWidget	*widget);
-GtkStyle*  gtk_widget_get_style		(GtkWidget	*widget);
+void        gtk_widget_style_attach       (GtkWidget            *style);
+
+gboolean    gtk_widget_has_rc_style       (GtkWidget            *widget);
+void	    gtk_widget_set_style          (GtkWidget            *widget,
+                                           GtkStyle             *style);
+void        gtk_widget_ensure_style       (GtkWidget            *widget);
+GtkStyle *  gtk_widget_get_style          (GtkWidget            *widget);
 
 void        gtk_widget_modify_style       (GtkWidget            *widget,
 					   GtkRcStyle           *style);