[coldsync-hackers] [patch] broken conduits exhaust resources

[Christophe Beauregard]

I discovered a couple of bugs with a seriously broken sync conduit.

First, a broken sync conduit that does an dlp_OpenDB without closing will
lock out all other SPC-capable sync conduits.

Second, too many SPC-capable sync conduits will exhaust file descriptors
because the SPC pipes (from socketpair) are never closed.

Attached is a patch for both problems and a sample conduit, syncjerk, that
shows the bug. If you configure syncjerk to sync a specific database (i.e.
type: mail/DATA) it'll exhaust dlp handles. If you configure it with
type:*/* (or any other SPC conduit, actually), it'll (eventually) exhaust
both file descriptors and dlp handles.

c.