Index: src/vehicle_cmd.cpp
===================================================================
--- src/vehicle_cmd.cpp	(revision 27675)
+++ src/vehicle_cmd.cpp	(working copy)
@@ -606,7 +606,7 @@
 	bool vehicle_list_window = HasBit(p1, 1);
 
 	VehicleListIdentifier vli;
-	if (!vli.Unpack(p2)) return CMD_ERROR;
+	if (!vli.UnpackIfValid(p2)) return CMD_ERROR;
 	if (!IsCompanyBuildableVehicleType(vli.vtype)) return CMD_ERROR;
 
 	if (vehicle_list_window) {
@@ -1001,7 +1001,7 @@
 	if (p1 & DEPOT_MASS_SEND) {
 		/* Mass goto depot requested */
 		VehicleListIdentifier vli;
-		if (!vli.Unpack(p2)) return CMD_ERROR;
+		if (!vli.UnpackIfValid(p2)) return CMD_ERROR;
 		return SendAllVehiclesToDepot(flags, (p1 & DEPOT_SERVICE) != 0, vli);
 	}
 
Index: src/vehicle_gui.cpp
===================================================================
--- src/vehicle_gui.cpp	(revision 27675)
+++ src/vehicle_gui.cpp	(working copy)
@@ -1638,7 +1638,7 @@
 				break;
 
 			case WID_VL_MANAGE_VEHICLES_DROPDOWN: {
-				DropDownList *list = this->BuildActionDropdownList(VehicleListIdentifier(this->window_number).type == VL_STANDARD, false);
+				DropDownList *list = this->BuildActionDropdownList(VehicleListIdentifier::UnPack(this->window_number).type == VL_STANDARD, false);
 				ShowDropDownList(this, list, 0, WID_VL_MANAGE_VEHICLES_DROPDOWN);
 				break;
 			}
Index: src/vehicle_gui_base.h
===================================================================
--- src/vehicle_gui_base.h	(revision 27675)
+++ src/vehicle_gui_base.h	(working copy)
@@ -38,7 +38,7 @@
 	static const StringID vehicle_sorter_names[];
 	static GUIVehicleList::SortFunction * const vehicle_sorter_funcs[];
 
-	BaseVehicleListWindow(WindowDesc *desc, WindowNumber wno) : Window(desc), vli(wno)
+	BaseVehicleListWindow(WindowDesc *desc, WindowNumber wno) : Window(desc), vli(VehicleListIdentifier::UnPack(wno))
 	{
 		this->vehicles.SetSortFuncs(this->vehicle_sorter_funcs);
 	}
Index: src/vehiclelist.cpp
===================================================================
--- src/vehiclelist.cpp	(revision 27675)
+++ src/vehiclelist.cpp	(working copy)
@@ -37,7 +37,7 @@
  * @param data The data to unpack.
  * @return true iff the data was valid (enough).
  */
-bool VehicleListIdentifier::Unpack(uint32 data)
+bool VehicleListIdentifier::UnpackIfValid(uint32 data)
 {
 	byte c        = GB(data, 28, 4);
 	this->company = c == 0xF ? OWNER_NONE : (CompanyID)c;
@@ -52,10 +52,12 @@
  * Decode a packed vehicle list identifier into a new one.
  * @param data The data to unpack.
  */
-VehicleListIdentifier::VehicleListIdentifier(uint32 data)
+/* static */ VehicleListIdentifier VehicleListIdentifier::UnPack(uint32 data)
 {
-	bool ret = this->Unpack(data);
+	VehicleListIdentifier result;
+	bool ret = result.UnpackIfValid(data);
 	assert(ret);
+	return result;
 }
 
 /**
Index: src/vehiclelist.h
===================================================================
--- src/vehiclelist.h	(revision 27675)
+++ src/vehiclelist.h	(working copy)
@@ -35,7 +35,8 @@
 	uint32 index;         ///< A vehicle list type specific index.
 
 	uint32 Pack() const;
-	bool Unpack(uint32 data);
+	bool UnpackIfValid(uint32 data);
+	static VehicleListIdentifier UnPack(uint32 data);
 
 	/**
 	 * Create a simple vehicle list.
@@ -47,7 +48,7 @@
 	VehicleListIdentifier(VehicleListType type, VehicleType vtype, CompanyID company, uint index = 0) :
 		type(type), vtype(vtype), company(company), index(index) {}
 
-	VehicleListIdentifier(uint32 data = 0);
+	VehicleListIdentifier() : type(), vtype(), company(), index() {}
 };
 
 /** A list of vehicles. */