Fix follower recursion

Content.Shared/Follower/Components/FollowedComponent.cs

@@ -1,13 +1,16 @@
 using System.Collections.Generic;
 using Robust.Shared.Analyzers;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 
 namespace Content.Shared.Follower.Components;
 
+// TODO properly network this and followercomp.
 /// <summary>
 ///     Attached to entities that are currently being followed by a ghost.
 /// </summary>
 [RegisterComponent, Friend(typeof(FollowerSystem))]
+[NetworkedComponent]
 public sealed class FollowedComponent : Component
 {
     public HashSet<EntityUid> Following = new();

Content.Shared/Follower/Components/FollowerComponent.cs

@@ -1,10 +1,12 @@
 using Robust.Shared.Analyzers;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 
 namespace Content.Shared.Follower.Components;
 
 [RegisterComponent]
 [Friend(typeof(FollowerSystem))]
+[NetworkedComponent]
 public sealed class FollowerComponent : Component
 {
     public EntityUid Following;

Content.Shared/Follower/FollowerSystem.cs

@@ -63,11 +63,16 @@ public sealed class FollowerSystem : EntitySystem
     /// <param name="entity">The entity to be followed</param>
     public void StartFollowingEntity(EntityUid follower, EntityUid entity)
     {
+        // No recursion for you
+        if (Transform(entity).ParentUid == follower)
+            return;
+
         var followerComp = EnsureComp<FollowerComponent>(follower);
         followerComp.Following = entity;
 
         var followedComp = EnsureComp<FollowedComponent>(entity);
-        followedComp.Following.Add(follower);
+        if (!followedComp.Following.Add(follower))
+            return;
 
         var xform = Transform(follower);
         xform.AttachParent(entity);