It is hard-coded to work with session numbers 1-8, and it may trash memory when passed higher session numbers. This was causing crashes after disconnecting in some cases.
This patch just bypasses the attention vector routine completely for DSI sessions (it's still called for sessions 1-8, i.e. ASP sessions). This should be OK, because its only real function was to display alerts about the connection being closed.
This tells the server to keep the session alive (typically for at least several hours) without sending or expecting tickles. This is useful in cases where our run queue procedure is not run regularly or at all, e.g. in text-mode shells.
The implementation here is geared toward compatibility with Netatalk and differs from Apple's published standards in a couple ways. It may or may not work with other servers.
This is necessary because FIListSessions2 has a bug that causes it to return garbage in the server/zone fields for DSI sessions. (The bug is essentially that PFI is indexing into its own tables based on the ASP/DSI session number, rather than properly using a PFI-level session index.)
Stephen Heumann