Issue #165: Re-validate ground bag window status on reconnect.

If we disconnect with an open ground bag, on reconnect the
bag or its contents may no longer be valid.  If the bags was closed
the state many still have changed.  If the window is open and there
is still a bag then re-validate its contents.  Otherwise close any
invalid open bag and/or clear the state of a previously opened bag.

bags.c

@@ -150,6 +150,31 @@ static float get_bag_tilt(float pos_x, float pos_y, int bag_id, int map_x, int m
 		digest[6]) + cosf(digest[7])) / 5.0f) * 30;
 }
 
+void revalidate_ground_bag_window(void)
+{
+	// never opened a bag window so nothing to do
+	if (get_id_MW(MW_BAGS) < 0)
+		return;
+
+	// if we are over an open bag, refresh its contents
+	if (your_actor && get_show_window_MW(MW_BAGS))
+	{
+		size_t i;
+		for (i = 0; i < NUM_BAGS; i++)
+			if ((bag_list[i].obj_3d_id != -1) &&
+				(bag_list[i].x == (your_actor->x_pos * 2)) &&
+				(bag_list[i].y == (your_actor->y_pos * 2)))
+			{
+				Uint8 str[2] = { INSPECT_BAG, i };
+				my_tcp_send(str, 2);
+				return;
+			}
+	}
+
+	// either we have an open window but no bag, or a previously opened window - clear the state
+	client_close_bag();
+}
+
 void put_bag_on_ground(int bag_x,int bag_y,int bag_id)
 {
 	float x,y,z;

bags.h

@@ -145,6 +145,14 @@ void server_close_bag(void);
  */
 void client_close_bag(void);
 
+/*!
+ * \ingroup item
+ * \brief   Revalidate ground bag window status on reconnect.
+ *
+ * \callgraph
+ */
+void revalidate_ground_bag_window(void);
+
 /*!
  * \ingroup item
  * \brief   Handle the inventory Get All button.

multiplayer.c

@@ -900,6 +900,7 @@ void process_message_from_server (const Uint8 *in_data, int data_length)
 				load_channel_colors();
 				send_video_info();
 				check_glow_perk();
+				revalidate_ground_bag_window();
 #ifdef USE_SSL
 				set_logged_in(1);
 #else // USE_SSL