(svn r14925) -Fix [FS#2500]: Abort dragging of vehicles in the group window when they are deleted.

src/group_gui.cpp

@@ -694,6 +694,16 @@ public:
 		this->vehicle_sel = INVALID_VEHICLE;
 		this->InvalidateWidget(GRP_WIDGET_LIST_VEHICLE);
 	}
+
+	/**
+	 * Tests whether a given vehicle is selected in the window, and unselects it if necessary.
+	 * Called when the vehicle is deleted.
+	 * @param vehicle Vehicle that is going to be deleted
+	 */
+	void UnselectVehicle(VehicleID vehicle)
+	{
+		if (this->vehicle_sel == vehicle) ResetObjectToPlace();
+	}
 };
 
 
@@ -712,3 +722,22 @@ void ShowCompanyGroup(CompanyID company, VehicleType vehicle_type)
 	WindowNumber num = (vehicle_type << 11) | VLW_GROUP_LIST | company;
 	AllocateWindowDescFront<VehicleGroupWindow>(&_group_desc, num);
 }
+
+/**
+ * Removes the highlight of a vehicle in a group window
+ * @param *v Vehicle to remove all highlights from
+ */
+void DeleteGroupHighlightOfVehicle(const Vehicle *v)
+{
+	VehicleGroupWindow *w;
+
+	/* If we haven't got any vehicles on the mouse pointer, we haven't got any highlighted in any group windows either
+	 * If that is the case, we can skip looping though the windows and save time
+	 */
+	if (_special_mouse_mode != WSM_DRAGDROP) return;
+
+	VehicleType vehicle_type = v->type;
+	w = dynamic_cast<VehicleGroupWindow *>(FindWindowById(GetWindowClassForVehicleType(vehicle_type), (vehicle_type << 11) | VLW_GROUP_LIST | v->owner));
+	if (w != NULL) w->UnselectVehicle(v->index);
+}
+

src/group_gui.h

@@ -8,5 +8,6 @@
 #include "vehicle_type.h"
 
 void ShowCompanyGroup(CompanyID company, VehicleType veh);
+void DeleteGroupHighlightOfVehicle(const Vehicle *v);
 
 #endif /* GROUP_GUI_H */

src/vehicle.cpp

@@ -32,6 +32,7 @@
 #include "newgrf_station.h"
 #include "newgrf_text.h"
 #include "group.h"
+#include "group_gui.h"
 #include "order_func.h"
 #include "strings_func.h"
 #include "zoom_func.h"
@@ -571,6 +572,7 @@ void Vehicle::PreDestructor()
 		GetCompany(this->owner)->num_engines[this->engine_type]--;
 		if (this->owner == _local_company) InvalidateAutoreplaceWindow(this->engine_type, this->group_id);
 
+		DeleteGroupHighlightOfVehicle(this);
 		if (IsValidGroupID(this->group_id)) GetGroup(this->group_id)->num_engines[this->engine_type]--;
 		if (this->IsPrimaryVehicle()) DecreaseGroupNumVehicle(this->group_id);
 	}