Terminate AI packages when target is disabled or deleted (Fixes #1910)

apps/openmw/mwmechanics/aiactivate.cpp

@@ -28,7 +28,10 @@ bool MWMechanics::AiActivate::execute (const MWWorld::Ptr& actor,float duration)
 
     actor.getClass().getCreatureStats(actor).setDrawState(DrawState_Nothing);
 
-    if(target == MWWorld::Ptr())
+    if(target == MWWorld::Ptr() ||
+        !target.getRefData().getCount() || !target.getRefData().isEnabled()  // Really we should be checking whether the target is currently registered
+                                                                            // with the MechanicsManager
+            )
         return true;   //Target doesn't exist
 
     //Set the target desition from the actor

apps/openmw/mwmechanics/aicombat.cpp

@@ -180,7 +180,9 @@ namespace MWMechanics
         if (target.isEmpty())
             return false;
 
-        if(target.getClass().getCreatureStats(target).isDead())
+        if(!target.getRefData().getCount() || !target.getRefData().isEnabled()  // Really we should be checking whether the target is currently registered
+                                                                                // with the MechanicsManager
+                || target.getClass().getCreatureStats(target).isDead())
             return true;
 
         const MWWorld::Class& actorClass = actor.getClass();

apps/openmw/mwmechanics/aifollow.cpp

@@ -45,7 +45,9 @@ bool MWMechanics::AiFollow::execute (const MWWorld::Ptr& actor,float duration)
 {
     MWWorld::Ptr target = getTarget();
 
-    if (target.isEmpty())
+    if (target.isEmpty() || !target.getRefData().getCount() || !target.getRefData().isEnabled()  // Really we should be checking whether the target is currently registered
+                                                                                                 // with the MechanicsManager
+            )
         return true; //Target doesn't exist
 
     // Only the player can be actively followed. AiFollow packages with targets other than the player

apps/openmw/mwmechanics/aipursue.cpp

@@ -38,7 +38,9 @@ bool AiPursue::execute (const MWWorld::Ptr& actor, float duration)
     ESM::Position pos = actor.getRefData().getPosition(); //position of the actor
     const MWWorld::Ptr target = MWBase::Environment::get().getWorld()->searchPtrViaActorId(mTargetActorId); //The target to follow
 
-    if(target == MWWorld::Ptr())
+    if(target == MWWorld::Ptr() || !target.getRefData().getCount() || !target.getRefData().isEnabled()  // Really we should be checking whether the target is currently registered
+                                                                                                        // with the MechanicsManager
+            )
         return true; //Target doesn't exist
 
     if(target.getClass().getCreatureStats(target).isDead())