If this is allowed, then the client usually gets forcibly logged out and data structures might be put into bad states.
To prevent this, the binary state machine of EMT.m_agentsInTransit is replaced with a 4 state machine (Preparing, Transferring, ReceivedAtDestination, CleaningUp).
This is necessary because the source region needs to know when the destination region has received the user but a teleport back cannot happen until the source region has cleaned up.
Tested on standalone, grid and with v1 and v3 clients.
This was due to two things
1) SimulationServiceConnector.QueryAccess was always looking to the outer result["success"].
But if a "_Result" map is returned (which is certainly the case right now), then the true success is _Result["success"], result["success"] is always true no matter what
2) If QueryAccess was false at the destination, then AgentHandlers.DoQueryAccess() was never putting this in the result.
The default action of SerializeJsonString() is not to put false booleans in the JSON!!!, so this has to be explicitly set.
This is to help relieve a race condition when an agent teleports then immediately attempts to teleport back before the source region has properly cleaned up/demoted the old ScenePresence.
This is rare in viewers but much more possible via scripting or region module.
However, more needs to be done since virtually all clean up happens after the transit flag is cleared .
Possibly need to add a 'cleaning up' state to in transit.
This change required making the EntityTransferModule and HGEntityTransferModule per-region rather than shared, in order to allow separate transit lists.
Changes were also required in LocalSimulationConnector.
Tested in standalone, grid and with local and remote region crossings with attachments.
This includes prim count, script count, avatar count, etc.
Information is currently the same as "show stats", though show stats can only show one scene at a time because it listens for the latest outgoing stats packet (a bad approach that needs to change).
Might be better to tie this module into the other stats module to display arbitrary stats rather than fetching directly from scene.SimStatsReporter.
Console command is "show scene" because "show region" already exists for the grid service, which is unfortunate.
Might need to make a distinction between "scene" relating to a live scene and "region" relating to more static region data (url, coords, etc.)
The reference is not guaranteed to be there when AddRegion() is called but will definitely be present at RegionLoaded() if it's going to be present at all.
This is because the attachments module code was setting the 'object slam' bit by using PermissionMask.All
Solution here is to route the attachment item creation call through the existing inventory code in BasicInventoryAccessModule rather than copy/pasted code in AttachmentsModule itself.
This is to eliminate possible race conditions if two teleport calls are made concurrently, where at least one is a local teleport.
This is pretty much impossible on a manual user teleport but can happen on script-invoked teleports.
Justin Clark-Casey (justincc)