(ITS#5814) concurrent access to connections

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD/re24
OS: irrelevant
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (81.72.89.40)
Submitted by: ando


There is code that accesses c_conn_state and c_struct_state while not adequately
mutex-protected.  In most cases, this code basically consists in assertions, so
we risk a core dump because of an assertion on non-mutex protected data.  This
is the case (as happened to me) of connection_next().

I have a fix for the case I noticed, with two unhandled asserts (marked with a
FIXME) because I'm not sure whether it's worth to add extra mutexes just to be
able to safely assert, or remove assertions.

Committing the fix; there might be more.  Please check.

p.