If we do this after TeleportFinish, then it's possible for a neighbour destination to request the source to create a child agent whilst its still treated as root.
This closes the original presence which we don't really want to do.
This is probably okay (albeit with warnings on the console) but afaics there's no reason not to move the child agent signal.
Also adds regression test for the case where the viewer couldn't connect with the destination region.
Also refactoring of regression test support code associated with entity transfer in order to make this test possible and the code less obscure.
This option allows the simulator to specify that the cancel button on inter-region teleports should never appear.
This exists because sometimes cancellation will result in a stuck avatar requiring relog.
It may be hard to prevent this due to the protocol design (the LL grid has the same issue)
In small controlled grids where teleport failure is practically impossible it can be better to disable teleport cancellation entirely.
Previously, hitting the cancel button on a teleport would cancel on the client side but the request was ignored on the server side.
Cancel would still work if the teleport failed in the early stages (e.g. because the destination never replied to early CreateAgent and UpdateAgent messages).
But if the teleport still completed after a delay here or later on, the viewer would become confused (usual symptom appears to be avatar being unable to move/reteleport).
This commit makes OpenSimulator obey cancellations which are received before it sends the TeleportFinish event queue message and does proper cleanup.
But cancellations received after this (which can happen even though the cancel button is removed as this messages comes on a different thread) can still result in a frozen avatar.
This looks extremely difficult and impossible to fix.
I can replicate the same problem on the Linden Lab grid by hitting cancel immediately after a teleport starts (a teleport which would otherwise quickly succeed).
This means that if such an exception does occur, the region does not need to be reset before that user can teleport from it again.
This is all Oren's code from his patch in http://opensimulator.org/mantis/view.php?id=6374 but I've chosen to split it in two.
I believe UseCircuitCode is sent on EnableSimulator EQ message, rather than EstablishAgentCommunication
At least with LL 3.3.4, EstablishAgentCommunication appears unnecessary in the teleport context -
viewer still requests it though possibly only after TeleportFinish(). However, we will continue to send it.
The viewer would not see the folder move without this, either on accept or decline.
This commit also updates the TaskInventoryOffered message to better conform with the data LL uses
Changes are, agentID is prim owner rather than prim id, agent name is now simply object name rather than name with owner detail,
message is just folder name in single quotes, message is not timestamped.
However, folder is not renamed "still #RLV/~<name>". Long term solution is probably not to do these operations server-side.
Notes will be added to http://opensimulator.org/mantis/view.php?id=6311
