[BUG] body.FixtureList can be null but OnDisable() doesn't handle that scenario

Xelnath

NullReferenceException: Object reference not set to an instance of an object
  at TrueSync.Physics2D.Body.set_Enabled (Boolean value) [0x0009e] in Z:\Projects\Atomech\project-sidescroller\Assets\Standard Assets\TrueSync\Physics\Farseer\Dynamics\Body.cs:420 
  at TrueSync.TSCollider2D.OnDisable () [0x00014] in Z:\Projects\Atomech\project-sidescroller\Assets\Standard Assets\TrueSync\Unity\TSCollider2D.cs:307 
UnityEngine.Object:Destroy(Object, Single)
UnityEngine.Object:Destroy(Object) (at C:\buildslave\unity\build\artifacts\generated\common\runtime\UnityEngineObjectBindings.gen.cs:83)
TrueSync.Physics2DWorldManager:OnRemovedRigidBody(Body) (at Z:\Projects\Atomech\project-sidescroller\Assets\Standard Assets\TrueSync\Unity\Physics2DWorldManager.cs:136)
TrueSync.Physics2D.World:ProcessRemovedBodies() (at Z:\Projects\Atomech\project-sidescroller\Assets\Standard Assets\TrueSync\Physics\Farseer\Dynamics\World.cs:383)
TrueSync.Physics2D.WorldClone2D:Restore(IWorld) (at Z:\Projects\Atomech\project-sidescroller\Assets\Standard Assets\TrueSync\Physics\Farseer\Extra\Clones\WorldClone2D.cs:176)
TrueSync.RollbackLockstep:RestorePreviousState()
TrueSync.RollbackLockstep:Rollback(Int32, Int32)
TrueSync.RollbackLockstep:BeforeStepUpdate(Int32, Int32)
TrueSync.AbstractLockstep:Update()
TrueSync.TrueSyncManager:FixedUpdate() (at Z:\Projects\Atomech\project-sidescroller\Assets\Standard Assets\TrueSync\Unity\TrueSyncManager.cs:724)

Culprit code is here:

        public bool Enabled
        {
            set
            {
                if (value == _enabled)
                    return;

                if (value)
                {
                    // Create all proxies.
                    IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
                    for (int i = 0; i < FixtureList.Count; i++)
                    {
                        FixtureList[i].CreateProxies(broadPhase, ref _xf);
                    }

                    // Contacts are created the next time step.
                }
                else
                {
                    // Destroy all proxies.
                    IBroadPhase broadPhase = _world.ContactManager.BroadPhase;

                    for (int i = 0; i < FixtureList.Count; i++)
                    {
                        FixtureList[i].DestroyProxies(broadPhase);
                    }

                    // Destroy the attached contacts.
                    ContactEdge ce = ContactList;
                    while (ce != null)
                    {
                        ContactEdge ce0 = ce;
                        ce = ce.Next;
                        _world.ContactManager.Destroy(ce0.Contact);
                    }
                    ContactList = null;
                }

                _enabled = value;
            }
            get { return _enabled; }
        }

As you can see, the FixtureList is not checked for a non-null value.

FixtureList can be made null by at least one place in
public void ProcessRemovedBodies() of World.cs

JeffersonHenrique

Thanks @Xelnath!!