IOBuffer was buggy if start_offset wasn't 0
IOBuffer was buggy if start_offset wasn't 0

damoxc/dovecot,LTD-Beget/dovecot,damoxc/dovecot,Distrotech/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,damoxc/dovecot,damoxc/dovecot,LTD-Beget/dovecot,Distrotech/dovecot,Distrotech/dovecot,LTD-Beget/dovecot,Distrotech/dovecot,damoxc/dovecot,Distrotech/dovecot