From 67643485ccf2a4906f0ef7e76e842a16cad87254 Mon Sep 17 00:00:00 2001
From: nsubiron <nsubiron@cvc.uab.es>
Date: Sat, 28 Jul 2018 13:04:14 +0200
Subject: [PATCH] Fix long-standing crash when a vehicle is destroyed

---
 .../Vehicle/WheeledVehicleAIController.cpp     | 18 ++++++++++++++++--
 .../Carla/Vehicle/WheeledVehicleAIController.h |  6 ++++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.cpp b/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.cpp
index f97a71e6c..f94283463 100644
--- a/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.cpp
+++ b/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.cpp
@@ -91,7 +91,8 @@ void AWheeledVehicleAIController::Possess(APawn *aPawn)
 {
   Super::Possess(aPawn);
 
-  if (IsPossessingAVehicle()) {
+  if (IsPossessingAVehicle())
+  {
     UE_LOG(LogCarla, Error, TEXT("Controller already possessing a vehicle!"));
     return;
   }
@@ -108,13 +109,26 @@ void AWheeledVehicleAIController::Possess(APawn *aPawn)
   }
 }
 
+void AWheeledVehicleAIController::UnPossess()
+{
+  Super::UnPossess();
+
+  Vehicle = nullptr;
+}
+
 void AWheeledVehicleAIController::Tick(const float DeltaTime)
 {
   Super::Tick(DeltaTime);
 
+  if (!IsPossessingAVehicle())
+  {
+    return;
+  }
+
   TickAutopilotController();
 
-  if (bAutopilotEnabled) {
+  if (bAutopilotEnabled)
+  {
     Vehicle->ApplyVehicleControl(AutopilotControl);
   }
 }
diff --git a/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.h b/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.h
index 2e7f36bf9..b80be8674 100644
--- a/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.h
+++ b/Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/WheeledVehicleAIController.h
@@ -42,9 +42,11 @@ public:
   /// @{
 public:
 
-  virtual void Possess(APawn *aPawn) override;
+  void Possess(APawn *aPawn) override;
 
-  virtual void Tick(float DeltaTime) override;
+  void UnPossess() override;
+
+  void Tick(float DeltaTime) override;
 
   /// @}
   // ===========================================================================