Index: src/build_vehicle_gui.cpp
===================================================================
--- src/build_vehicle_gui.cpp	(revision 12791)
+++ src/build_vehicle_gui.cpp	(working copy)
@@ -53,6 +53,7 @@
 	BUILD_VEHICLE_WIDGET_CAPTION,
 	BUILD_VEHICLE_WIDGET_SORT_ASSENDING_DESCENDING,
 	BUILD_VEHICLE_WIDGET_SORT_DROPDOWN,
+	BUILD_VEHICLE_WIDGET_CARGO_DROPDOWN,
 	BUILD_VEHICLE_WIDGET_LIST,
 	BUILD_VEHICLE_WIDGET_SCROLLBAR,
 	BUILD_VEHICLE_WIDGET_PANEL,
@@ -64,19 +65,31 @@
 
 static const Widget _build_vehicle_widgets[] = {
 	{   WWT_CLOSEBOX,   RESIZE_NONE,    14,     0,    10,     0,    13, STR_00C5,                STR_018B_CLOSE_WINDOW },
-	{    WWT_CAPTION,  RESIZE_RIGHT,    14,    11,   239,     0,    13, 0x0,                     STR_018C_WINDOW_TITLE_DRAG_THIS },
-	{ WWT_PUSHTXTBTN,   RESIZE_NONE,    14,     0,    80,    14,    25, STR_SORT_BY,             STR_SORT_ORDER_TIP},
-	{   WWT_DROPDOWN,  RESIZE_RIGHT,    14,    81,   239,    14,    25, 0x0,                     STR_SORT_CRITERIA_TIP},
-	{     WWT_MATRIX,     RESIZE_RB,    14,     0,   227,    26,    39, 0x101,                   STR_NULL },
-	{  WWT_SCROLLBAR,    RESIZE_LRB,    14,   228,   239,    26,    39, 0x0,                     STR_0190_SCROLL_BAR_SCROLLS_LIST },
-	{      WWT_PANEL,    RESIZE_RTB,    14,     0,   239,    40,   161, 0x0,                     STR_NULL },
+	{    WWT_CAPTION,  RESIZE_RIGHT,    14,    11,   293,     0,    13, 0x0,                     STR_018C_WINDOW_TITLE_DRAG_THIS },
+	{ WWT_PUSHTXTBTN,   RESIZE_NONE,    14,     0,    60,    14,    25, STR_SORT_BY,             STR_SORT_ORDER_TIP},
+	{   WWT_DROPDOWN,   RESIZE_NONE,    14,    61,   190,    14,    25, 0x0,                     STR_SORT_CRITERIA_TIP},
+	{   WWT_DROPDOWN,  RESIZE_RIGHT,    14,   191,   293,    14,    25, 0x0,                     STR_SORT_CRITERIA_TIP},
+	{     WWT_MATRIX,     RESIZE_RB,    14,     0,   281,    26,    39, 0x101,                   STR_NULL },
+	{  WWT_SCROLLBAR,    RESIZE_LRB,    14,   282,   293,    26,    39, 0x0,                     STR_0190_SCROLL_BAR_SCROLLS_LIST },
+	{      WWT_PANEL,    RESIZE_RTB,    14,     0,   293,    40,   161, 0x0,                     STR_NULL },
 
-	{ WWT_PUSHTXTBTN,     RESIZE_TB,    14,     0,   114,   162,   173, 0x0,                     STR_NULL },
-	{ WWT_PUSHTXTBTN,    RESIZE_RTB,    14,   115,   227,   162,   173, 0x0,                     STR_NULL },
-	{  WWT_RESIZEBOX,   RESIZE_LRTB,    14,   228,   239,   162,   173, 0x0,                     STR_RESIZE_BUTTON },
+	{ WWT_PUSHTXTBTN,     RESIZE_TB,    14,     0,   114,   162,   173, 0x0,                         STR_NULL },
+	{ WWT_PUSHTXTBTN,    RESIZE_RTB,    14,   115,   281,   162,   173, 0x0,                         STR_NULL },
+	{  WWT_RESIZEBOX,   RESIZE_LRTB,    14,   282,   293,   162,   173, 0x0,                         STR_RESIZE_BUTTON },
 	{   WIDGETS_END},
 };
 
+enum cargo_filter {
+	CF_SHOW_ALL = -1
+};
+
+static int _cargo_filter_train = CF_SHOW_ALL;
+static int _cargo_filter_road = CF_SHOW_ALL;
+static int _cargo_filter_ship = CF_SHOW_ALL;
+static int _cargo_filter_aircraft = CF_SHOW_ALL;
+static StringID _cargos_name_list[NUM_CARGO + 1];
+static int _cargos_dropdown_pos[NUM_CARGO + 1];
+
 /* Setup widget strings to fit the different types of vehicles */
 static void SetupWindowStrings(Window *w, VehicleType type)
 {
@@ -807,6 +820,9 @@
 		if (bv->filter.railtype != RAILTYPE_END && !HasPowerOnRail(rvi->railtype, bv->filter.railtype)) continue;
 		if (!IsEngineBuildable(eid, VEH_TRAIN, _local_player)) continue;
 
+		uint32 cmask = EngInfo(eid)->refit_mask;
+		if (!((_cargo_filter_train == rvi->cargo_type && rvi->capacity > 0) || (HasBit(cmask, _cargo_filter_train))) && (_cargo_filter_train > CF_SHOW_ALL )) continue;
+
 		EngList_Add(&bv->eng_list, eid);
 		if (rvi->railveh_type != RAILVEH_WAGON) {
 			num_engines++;
@@ -841,8 +857,14 @@
 
 	EngineID eid;
 	FOR_ALL_ENGINEIDS_OF_TYPE(eid, VEH_ROAD) {
+		const RoadVehicleInfo *rvi = RoadVehInfo(eid);
+
 		if (!IsEngineBuildable(eid, VEH_ROAD, _local_player)) continue;
 		if (!HasBit(bv->filter.roadtypes, HasBit(EngInfo(eid)->misc_flags, EF_ROAD_TRAM) ? ROADTYPE_TRAM : ROADTYPE_ROAD)) continue;
+
+		uint32 cmask = EngInfo(eid)->refit_mask;
+		if (!((_cargo_filter_road == rvi->cargo_type && rvi->capacity > 0) || (HasBit(cmask, _cargo_filter_road))) && (_cargo_filter_road > CF_SHOW_ALL )) continue;
+
 		EngList_Add(&bv->eng_list, eid);
 
 		if (eid == bv->sel_engine) sel_id = eid;
@@ -860,7 +882,13 @@
 
 	EngineID eid;
 	FOR_ALL_ENGINEIDS_OF_TYPE(eid, VEH_SHIP) {
+		const ShipVehicleInfo *svi = ShipVehInfo(eid);
+
 		if (!IsEngineBuildable(eid, VEH_SHIP, _local_player)) continue;
+
+		uint32 cmask = EngInfo(eid)->refit_mask;
+		if (!((_cargo_filter_ship == svi->cargo_type && svi->capacity > 0) || (HasBit(cmask, _cargo_filter_ship))) && (_cargo_filter_ship > CF_SHOW_ALL )) continue;
+
 		EngList_Add(&bv->eng_list, eid);
 
 		if (eid == bv->sel_engine) sel_id = eid;
@@ -882,10 +910,15 @@
 	 * when planes become obsolete and are removed */
 	EngineID eid;
 	FOR_ALL_ENGINEIDS_OF_TYPE(eid, VEH_AIRCRAFT) {
+		const AircraftVehicleInfo *avi = AircraftVehInfo(eid);
+
 		if (!IsEngineBuildable(eid, VEH_AIRCRAFT, _local_player)) continue;
 		/* First VEH_END window_numbers are fake to allow a window open for all different types at once */
 		if (w->window_number > VEH_END && !CanAircraftUseStation(eid, w->window_number)) continue;
 
+		uint32 cmask = EngInfo(eid)->refit_mask;
+		if (!((_cargo_filter_aircraft == CT_PASSENGERS && avi->passenger_capacity > 0) || (_cargo_filter_aircraft == CT_MAIL && avi->mail_capacity > 0) || (HasBit(cmask, _cargo_filter_aircraft))) && (_cargo_filter_aircraft > CF_SHOW_ALL )) continue;
+
 		EngList_Add(&bv->eng_list, eid);
 		if (eid == bv->sel_engine) sel_id = eid;
 	}
@@ -990,6 +1023,15 @@
 	const buildvehicle_d *bv = &WP(w, buildvehicle_d);
 	uint max = min(w->vscroll.pos + w->vscroll.cap, EngList_Count(&bv->eng_list));
 
+	int cargo_filter = CF_SHOW_ALL;
+	switch (bv->vehicle_type) {
+		default: NOT_REACHED();
+		case VEH_TRAIN:    cargo_filter = _cargo_filter_train;    break;
+		case VEH_ROAD:     cargo_filter = _cargo_filter_road;     break;
+		case VEH_SHIP:     cargo_filter = _cargo_filter_ship;     break;
+		case VEH_AIRCRAFT: cargo_filter = _cargo_filter_aircraft; break;
+	}
+
 	w->SetWidgetDisabledState(BUILD_VEHICLE_WIDGET_BUILD, w->window_number <= VEH_END);
 
 	SetVScrollCount(w, EngList_Count(&bv->eng_list));
@@ -997,6 +1039,7 @@
 
 	/* Set text of sort by dropdown */
 	w->widget[BUILD_VEHICLE_WIDGET_SORT_DROPDOWN].data = _sort_listing[bv->vehicle_type][bv->sort_criteria];
+	w->widget[BUILD_VEHICLE_WIDGET_CARGO_DROPDOWN].data = _cargos_name_list[_cargos_dropdown_pos[cargo_filter]];
 
 	DrawWindowWidgets(w);
 
@@ -1039,6 +1082,19 @@
 		case BUILD_VEHICLE_WIDGET_SORT_DROPDOWN: // Select sorting criteria dropdown menu
 			ShowDropDownMenu(w, _sort_listing[bv->vehicle_type], bv->sort_criteria, BUILD_VEHICLE_WIDGET_SORT_DROPDOWN, 0, 0);
 			break;
+		
+		case BUILD_VEHICLE_WIDGET_CARGO_DROPDOWN: {
+			int cargo_filter = CF_SHOW_ALL;
+			switch (bv->vehicle_type) {
+				default: NOT_REACHED();
+				case VEH_TRAIN:    cargo_filter = _cargo_filter_train;    break;
+				case VEH_ROAD:     cargo_filter = _cargo_filter_road;     break;
+				case VEH_SHIP:     cargo_filter = _cargo_filter_ship;     break;
+				case VEH_AIRCRAFT: cargo_filter = _cargo_filter_aircraft; break;
+			}
+			ShowDropDownMenu(w, _cargos_name_list, _cargos_dropdown_pos[cargo_filter], BUILD_VEHICLE_WIDGET_CARGO_DROPDOWN, 0, 0);
+			break;
+		}
 
 		case BUILD_VEHICLE_WIDGET_BUILD: {
 			EngineID sel_eng = bv->sel_engine;
@@ -1148,11 +1204,40 @@
 		}
 
 		case WE_DROPDOWN_SELECT: // we have selected a dropdown item in the list
-			if (bv->sort_criteria != e->we.dropdown.index) {
-				bv->sort_criteria = e->we.dropdown.index;
-				_last_sort_criteria[bv->vehicle_type] = bv->sort_criteria;
-				bv->regenerate_list = true;
-			}
+			switch (e->we.dropdown.button) {
+			case BUILD_VEHICLE_WIDGET_SORT_DROPDOWN:
+				if (bv->sort_criteria != e->we.dropdown.index) {
+					bv->sort_criteria = e->we.dropdown.index;
+					_last_sort_criteria[bv->vehicle_type] = bv->sort_criteria;
+				}				
+				break;			
+			case BUILD_VEHICLE_WIDGET_CARGO_DROPDOWN:
+				CargoID c;
+				int cargo_filter;
+				
+				if (e->we.dropdown.index > 0) {
+					int i = 1;
+					for (c = 0; c < NUM_CARGO; c++) {
+						if (!GetCargo(c)->IsValid()) continue;
+						if (e->we.dropdown.index == i) break;
+						i++;
+					}
+					cargo_filter = c;
+				}
+				else {
+					cargo_filter = CF_SHOW_ALL;
+				}
+
+				switch (bv->vehicle_type) {
+					default: NOT_REACHED();
+					case VEH_TRAIN:    _cargo_filter_train = cargo_filter;    break;
+					case VEH_ROAD:     _cargo_filter_road = cargo_filter;     break;
+					case VEH_SHIP:     _cargo_filter_ship = cargo_filter;     break;
+					case VEH_AIRCRAFT: _cargo_filter_aircraft = cargo_filter; break;
+				}				
+				break;
+			}	
+			bv->regenerate_list = true;
 			SetWindowDirty(w);
 			break;
 
@@ -1167,7 +1252,7 @@
 }
 
 static const WindowDesc _build_vehicle_desc = {
-	WDP_AUTO, WDP_AUTO, 240, 174, 240, 256,
+	WDP_AUTO, WDP_AUTO, 294, 174, 294, 256,
 	WC_BUILD_VEHICLE, WC_NONE,
 	WDF_STD_TOOLTIPS | WDF_STD_BTN | WDF_DEF_WIDGET | WDF_UNCLICK_BUTTONS | WDF_RESIZABLE,
 	_build_vehicle_widgets,
@@ -1192,6 +1277,21 @@
 
 	if (w == NULL) return;
 
+	/* Create cargo filter list  */
+	_cargos_name_list[0] = STR_PURCHASE_INFO_ALL_TYPES;
+	_cargos_dropdown_pos[CF_SHOW_ALL] = 0;
+
+	uint i = 1;
+	for (CargoID c = 0; c < NUM_CARGO; c++) {
+		if (!GetCargo(c)->IsValid()) continue;
+		
+		_cargos_name_list[i] = GetCargo(c)->name;
+		_cargos_dropdown_pos[c] = i;
+
+		i++;
+	}
+	_cargos_name_list[i] = INVALID_STRING_ID;
+
 	w->caption_color = (tile != 0) ? GetTileOwner(tile) : _local_player;
 
 	bv = &WP(w, buildvehicle_d);