- Rename Map::CanEnter to Map::CannotEnter. Return value changed from boolean (true means player can enter) to enum Map::EnterState (CAN_ENTER=0 means player can enter, any other value is a reason for deny).
- Move hack-y player error messages from within Map::CanEnter to the function calling CanEnter as appropriate (primarily WorldSession::HandleAreaTriggerOpcode).
- Modify WorldSession::HandleAreaTriggerOpcode to properly revive the player upon touching the portal leading to the instance they died in even if they are currently unable to zone in. Fixes and closes#15758.
- Modify Player::LoadFromDB to properly spawn players in the instance they logged off in if possible. Fixes and closes#15561.
- Modify permanent save behavior to be blizzlike: Players can always enter an instance they are saved to (assuming there are no map constraints against it), but get a homebind timer if the instance is already in use.