That patch solves the problem for me, now dovecot ldap auth works. Thank you Timo.http://hg.dovecot.org/dovecot-2.0/rev/b44ec48d9425 probably fixes it?
(I was going to test that broken change when I made it, but then I realized I didn't have LDAP server installed and I just hate installing slapd. Today I thought I'd rather try writing my own really simple LDAP server, but after a few hours I gave up on it too. Maybe some day I'll try again. So the above patch is also untested.)
