(ITS#8585) assert in ber_get_next after connection error

[hyc@openldap.org]

Full_Name: Howard Chu
Version: any
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (195.235.15.200)
Submitted by: hyc


1) ldap_result() returns -1 with ld_errno = LDAP_LOCAL_ERROR because it read an
unrecognizable message from the network.
2) ldap_result() is called again on the same LDAP*.

During (1) the lc->lconn_ber was not zeroed out so it is used again in (2). But
ber_get_next() already fully parsed its input during (1) so this assert fails on
the 2nd call:

513		if (ber->ber_rwptr == NULL) {
514			assert( ber->ber_buf == NULL );
515			ber->ber_rwptr = (char *) &ber->ber_len-1;
516			ber->ber_ptr = ber->ber_ptr%r;
517			ber->ber_tag = 0;
518		}

ldap_result() should clear lconn_ber before returning with an error.

The LDAP* session probably should not be used again after (1) anyway but this is
still messy.