lib: istream-tee wasn't returning data correctly always. This fixes an assert-crash in istream-tee.c. (Hopefully it was always assert-crashing instead of returning corrupted data.)
lib: istream-tee wasn't returning data correctly always.
This fixes an assert-crash in istream-tee.c. (Hopefully it was always
assert-crashing instead of returning corrupted data.)

jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch