Enable NewGRF debug window for non-GRF vehicles

src/newgrf_debug_gui.cpp

@@ -201,6 +201,7 @@ public:
 	}
 
 	virtual void ExtraInfo(uint index, std::function<void(const char *)> print) const {}
+	virtual bool ShowExtraInfoOnly(uint index) const { return false; };
 
 protected:
 	/**
@@ -473,6 +474,8 @@ struct NewGRFInspectWindow : Window {
 			::DrawString(r.left + LEFT_OFFSET, r.right - RIGHT_OFFSET, r.top + TOP_OFFSET + (offset * this->resize.step_height), buf, TC_BLACK);
 		});
 
+		if (nih->ShowExtraInfoOnly(index)) return;
+
 		const_cast<NewGRFInspectWindow*>(this)->first_variable_line_index = i;
 
 		if (nif->variables != NULL) {

src/table/newgrf_debug_data.h

@@ -69,7 +69,8 @@ static const NIVariable _niv_vehicles[] = {
 };
 
 class NIHVehicle : public NIHelper {
-	bool IsInspectable(uint index) const                 { return Vehicle::Get(index)->GetGRF() != NULL; }
+	bool IsInspectable(uint index) const                 { return true; }
+	bool ShowExtraInfoOnly(uint index) const             { return Vehicle::Get(index)->GetGRF() == NULL; }
 	uint GetParent(uint index) const                     { const Vehicle *first = Vehicle::Get(index)->First(); return GetInspectWindowNumber(GetGrfSpecFeature(first->type), first->index); }
 	const void *GetInstance(uint index)const             { return Vehicle::Get(index); }
 	const void *GetSpec(uint index) const                { return Vehicle::Get(index)->GetEngine(); }