mongodb/node-mongodb-native — pull request #741 by m4tty (2012-10-22 03:45:23+00:00)
Title: Using ReadPreference.Secondary causes issues if read_secondary is not supplied with true

Allowed for leaving read_secondary option off of ReplicaSet constructor as we have enough information from the new ReadPreference object to know the secondary allowed setting.

Supplying ReadPreference.SecondaryWhatever without read_secondary=true causes allRawConnections() to return with no secondaries in the connections list (to db.authenticate()) and ultimately cause unauthenticated servers to be in the replicaset connection pool but still used and ultimately downstream auth failures.