This also makes the detection in SP.FindNextAvailableSitTarget() and SendSitResponse() identical.
Previously they varied slightly (SendSitResponse didn't check for an older type of invalid quaternion) but the practical effect is most probably zero.
This is to fix a regression starting from 5301648 where attachments had to start being deleted before persistence in order to avoid race conditions with hud update threads.
This prevents a stack overflow where a get position on the avatar will refer to the attachment which will in turn refer back to the avatar.
This required recording of all sitting avatars on a prim which is done separately from recording the sit target avatar.
Recording HashSet is null if there are no sitting avatars in order to save memory.
This is always done later on in SceneGraph.AddSceneObject() if the call hasn't failed due to sanity checks.
There's no other purpose for this method to exist and it's dangerous/pointless to call in other conditions.
This works like osForceAttachToAvatar() but allows an object to be directly specified from the script object's inventory rather than forcing it to be rezzed in the scene first.
Still only attaches objects to the owner of the script.
This allows one to bypass the complicated co-ordination of first rezzing objects in the scene before attaching them.
Threat level high.
If delete doesn't occur first then the update thread can outrace the IsAttachment = false necessary to save attachments and send hud artifacts to other viewers.
Serialization of attachments requires IsAttachment = false so that correct positions are serialized instead of avatar position.
However, doing this when a hud is still attached allows race conditions with update threads, resulting in hud artifacts on other viewers.
This change sets SOG.IsDeleted before serialization changes take place (IsDeleted itself is not a serialized property).
LLClientView then screens out any deleted SOGs before sending updates to viewers.
Change SOP.SendFullUpdateToClient() and SoundModule.PlayAttachedSound() to use this rather than different magic number formulations.
This also corrects a bug in PlayAttachedSound() where the code assumed that all attachment points over 30 were HUDs.
It appears this is no longer true with Neck and Root (Avatar Center)
Stop checking IsLoggingOut on these listeners, if called with a root agent then we always want to perform these actions.
This covers cases where the client is closed due to manual kick, simulator shutdown, etc.
This is always done as part of Scene.RemoveClient()
Also refactors try/catching in Scene.RemoveClient() to log NREs instead of silently discarding, since these are useful symptoms of problems.
This is done by making the kick user command call IClientAPI.Close() rather than routing through Scene.IncomingCloseAgent(), which also called IClientAPI.Close()
DisableSimulator for child agents is moved from IncomingCloseAgent() to RemoveClient(), this is not a functional change since IncomingCloseAgent() always ends up calling RemoveClient()
This makes frame time stats properly tally with fps, which saves confusion and makes it easier to interpret numbers.
In some ways this is not so artifical - physics FPS runs at the higher rate.
This is to make these statistics actually match their names (and also be more accurate as number of frames can vary under heavy load)
Currently using scene frames (11.23 every second) instead of physics frames (56.18 per second)
