From 433484cda3c1cecc0441dc0080c1cb1a765cf807 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Wed, 27 Mar 2024 20:20:27 +0000
Subject: [PATCH] Fix #12388: Vehicle::CopyVehicleConfigAndStatistics not
 releasing unit number (#12389)

---
 src/train_cmd.cpp  | 3 +--
 src/vehicle.cpp    | 9 +++++++++
 src/vehicle_base.h | 3 +++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 4413a2e777..51353c5281 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -1336,8 +1336,7 @@ CommandCost CmdMoveRailVehicle(DoCommandFlag flags, VehicleID src_veh, VehicleID
 			}
 			/* Remove stuff not valid anymore for non-front engines. */
 			DeleteVehicleOrders(src);
-			Company::Get(src->owner)->freeunits[src->type].ReleaseID(src->unitnumber);
-			src->unitnumber = 0;
+			src->ReleaseUnitNumber();
 			src->name.clear();
 		}
 
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 044c8013c9..7d6e8489ea 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -2401,6 +2401,15 @@ void Vehicle::ResetRefitCaps()
 	for (Vehicle *v = this; v != nullptr; v = v->Next()) v->refit_cap = v->cargo_cap;
 }
 
+/**
+ * Release the vehicle's unit number.
+ */
+void Vehicle::ReleaseUnitNumber()
+{
+	Company::Get(this->owner)->freeunits[this->type].ReleaseID(this->unitnumber);
+	this->unitnumber = 0;
+}
+
 /**
  * Handle the loading of the vehicle; when not it skips through dummy
  * orders and does nothing in all other cases.
diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index 3c4e2ea65f..592063323c 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -750,6 +750,8 @@ public:
 
 	void ResetRefitCaps();
 
+	void ReleaseUnitNumber();
+
 	/**
 	 * Copy certain configurations and statistics of a vehicle after successful autoreplace/renew
 	 * The function shall copy everything that cannot be copied by a command (like orders / group etc),
@@ -760,6 +762,7 @@ public:
 	{
 		this->CopyConsistPropertiesFrom(src);
 
+		this->ReleaseUnitNumber();
 		this->unitnumber = src->unitnumber;
 
 		this->current_order = src->current_order;