[nautilus] icon-dnd: don't set 'Set as Background' sensitive outside the desktop

[Cosimo Cecchi <cosimoc src gnome org>]

commit ab1229476f949fef5cd51545088c91c649be2ef1
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Tue Sep 28 14:50:15 2010 +0200

    icon-dnd: don't set 'Set as Background' sensitive outside the desktop

 libnautilus-private/nautilus-icon-dnd.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/libnautilus-private/nautilus-icon-dnd.c b/libnautilus-private/nautilus-icon-dnd.c
index 3e2a6a4..2fb42a6 100644
--- a/libnautilus-private/nautilus-icon-dnd.c
+++ b/libnautilus-private/nautilus-icon-dnd.c
@@ -1081,7 +1081,7 @@ nautilus_icon_container_receive_dropped_icons (NautilusIconContainer *container,
 					       GdkDragContext *context,
 					       int x, int y)
 {
-	char *drop_target;
+	char *drop_target, *container_uri;
 	gboolean local_move_only;
 	double world_x, world_y;
 	gboolean icon_hit;
@@ -1104,10 +1104,14 @@ nautilus_icon_container_receive_dropped_icons (NautilusIconContainer *container,
 			action = GDK_ACTION_MOVE;
 		} else {
 			action = GDK_ACTION_MOVE | GDK_ACTION_COPY | GDK_ACTION_LINK;
+			container_uri = get_container_uri (container);
 			
-			if (selection_is_image_file (container->details->dnd_info->drag_info.selection_list)) {
+			if (eel_uri_is_desktop (container_uri) &&
+			    selection_is_image_file (container->details->dnd_info->drag_info.selection_list)) {
 				action |= NAUTILUS_DND_ACTION_SET_AS_BACKGROUND;
 			}
+
+			g_free (container_uri);
 		}
 		real_action = nautilus_drag_drop_action_ask
 			(GTK_WIDGET (container), action);