--- a/src/misc_gui.cpp	Thu May 08 14:04:52 2008 +0000
+++ b/src/misc_gui.cpp	Thu May 08 14:14:16 2008 +0000
@@ -97,8 +97,7 @@
 {
 	DeleteWindowById(WC_LAND_INFO, 0);
 
-	Window *w = new Window(&_land_info_desc);
-	WP(w, void_d).data = &_landinfo_data;
+	new Window(&_land_info_desc);
 
 	Player *p = GetPlayer(IsValidPlayer(_local_player) ? _local_player : PLAYER_FIRST);
 	Town *t = ClosestTownFromTile(tile, _patches.dist_local_authority);
@@ -202,6 +201,12 @@
 	}
 }
 
+struct scroller_d {
+	int height;
+	uint16 counter;
+};
+assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(scroller_d));
+
 static const char *credits[] = {
 	/*************************************************************************
 	 *                      maximum length of string which fits in window   -^*/
@@ -519,6 +524,13 @@
 	if (te_id != INVALID_TE_ID) RemoveTextEffect(te_id);
 }
 
+struct tooltips_d {
+	StringID string_id;
+	byte paramcount;
+	uint64 params[5];
+};
+assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(tooltips_d));
+
 static const Widget _tooltips_widgets[] = {
 {      WWT_PANEL,   RESIZE_NONE,    14,     0,   199,     0,    31, 0x0, STR_NULL},
 {   WIDGETS_END},

--- a/src/player_gui.cpp	Thu May 08 14:04:52 2008 +0000
+++ b/src/player_gui.cpp	Thu May 08 14:14:16 2008 +0000
@@ -42,6 +42,12 @@
 };
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(facesel_d));
 
+struct highscore_d {
+	uint32 background_img;
+	int8 rank;
+};
+assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(highscore_d));
+
 enum {
 	FIRST_GUI_CALL = INT_MAX,  ///< default value to specify thuis is the first call of the resizable gui
 };

--- a/src/smallmap_gui.cpp	Thu May 08 14:04:52 2008 +0000
+++ b/src/smallmap_gui.cpp	Thu May 08 14:14:16 2008 +0000
@@ -32,6 +32,13 @@
 #include "table/strings.h"
 #include "table/sprites.h"
 
+struct smallmap_d {
+	int32 scroll_x;
+	int32 scroll_y;
+	int32 subscroll;
+};
+assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(smallmap_d));
+
 static const Widget _smallmap_widgets[] = {
 {  WWT_CLOSEBOX,   RESIZE_NONE,    13,     0,    10,     0,    13, STR_00C5,                STR_018B_CLOSE_WINDOW},
 {   WWT_CAPTION,  RESIZE_RIGHT,    13,    11,   337,     0,    13, STR_00B0_MAP,            STR_018C_WINDOW_TITLE_DRAG_THIS},

--- a/src/vehicle_gui.cpp	Thu May 08 14:04:52 2008 +0000
+++ b/src/vehicle_gui.cpp	Thu May 08 14:14:16 2008 +0000
@@ -40,6 +40,11 @@
 #include "table/sprites.h"
 #include "table/strings.h"
 
+struct vehicledetails_d {
+	byte tab;
+};
+assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(vehicledetails_d));
+
 struct refit_d {
 	int sel;
 	struct RefitOption *cargo;

--- a/src/window_gui.h	Thu May 08 14:04:52 2008 +0000
+++ b/src/window_gui.h	Thu May 08 14:14:16 2008 +0000
@@ -379,18 +379,6 @@
 };
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(def_d));
 
-struct void_d {
-	void *data;
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(void_d));
-
-struct tooltips_d {
-	StringID string_id;
-	byte paramcount;
-	uint64 params[5];
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(tooltips_d));
-
 struct depot_d {
 	VehicleID sel;
 	VehicleType type;
@@ -404,18 +392,6 @@
 };
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(depot_d));
 
-struct vehicledetails_d {
-	byte tab;
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(vehicledetails_d));
-
-struct smallmap_d {
-	int32 scroll_x;
-	int32 scroll_y;
-	int32 subscroll;
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(smallmap_d));
-
 struct vp_d {
 	VehicleID follow_vehicle;
 	int32 scrollpos_x;
@@ -426,18 +402,6 @@
 };
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(vp_d));
 
-struct highscore_d {
-	uint32 background_img;
-	int8 rank;
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(highscore_d));
-
-struct scroller_d {
-	int height;
-	uint16 counter;
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(scroller_d));
-
 enum SortListFlags {
 	VL_NONE    = 0,      ///< no sort
 	VL_DESC    = 1 << 0, ///< sort descending or ascending
@@ -461,13 +425,6 @@
 };
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(list_d));
 
-struct message_d {
-	int msg;
-	int wparam;
-	int lparam;
-};
-assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(message_d));
-
 struct vehiclelist_d {
 	const Vehicle** sort_list;  // List of vehicles (sorted)
 	Listing *_sorting;          // pointer to the appropiate subcategory of _sorting