index/imapc/imapc-mail-fetch.c

	imapc-mail-fetch.c revision 0f641fb49bf0a934556717a2c209566ac387d7bb
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen/* Copyright (c) 2011-2013 Dovecot authors, see the included COPYING file */
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen#include "lib.h"
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen#include "str.h"
d4c3d55021bcbf2b062f4782b1cde9115d35aefcTimo Sirainen#include "istream.h"
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen#include "istream-header-filter.h"
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen#include "message-header-parser.h"
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen#include "imap-arg.h"
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen#include "imap-date.h"
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen#include "imap-quote.h"
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen#include "imapc-client.h"
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen#include "imapc-mail.h"
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen#include "imapc-storage.h"
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainenstatic void
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainenimapc_mail_prefetch_callback(const struct imapc_command_reply *reply,
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen                 void *context)
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen{
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    struct imapc_mail *mail = context;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    struct imapc_mailbox *mbox =
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        (struct imapc_mailbox *)mail->imail.mail.mail.box;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    i_assert(mail->fetch_count > 0);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (--mail->fetch_count == 0) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        struct imapc_mail *const *fetch_mails;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        unsigned int i, count;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        fetch_mails = array_get(&mbox->fetch_mails, &count);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        for (i = 0; i < count; i++) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen            if (fetch_mails[i] == mail) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen                array_delete(&mbox->fetch_mails, i, 1);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen                break;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen            }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        i_assert(i != count);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        mail->fetching_fields = 0;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (reply->state == IMAPC_COMMAND_STATE_OK)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        ;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    else if (reply->state == IMAPC_COMMAND_STATE_NO) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        imapc_copy_error_from_reply(mbox->storage, MAIL_ERROR_PARAMS,
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen                        reply);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    } else if (reply->state == IMAPC_COMMAND_STATE_DISCONNECTED) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        /* The disconnection message was already logged */
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        mail_storage_set_internal_error(&mbox->storage->storage);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    } else {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        mail_storage_set_critical(&mbox->storage->storage,
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            "imapc: Mail prefetch failed: %s", reply->text_full);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    pool_unref(&mail->imail.mail.pool);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    imapc_client_stop(mbox->storage->client->client);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen}
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainenstatic bool
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainenheaders_have_subset(const char *const *superset, const char *const *subset)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen{
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    unsigned int i;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (superset == NULL)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        return FALSE;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (subset != NULL) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        for (i = 0; subset[i] != NULL; i++) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            if (!str_array_icase_find(superset, subset[i]))
d4c3d55021bcbf2b062f4782b1cde9115d35aefcTimo Sirainen                return FALSE;
d4c3d55021bcbf2b062f4782b1cde9115d35aefcTimo Sirainen        }
d4c3d55021bcbf2b062f4782b1cde9115d35aefcTimo Sirainen    }
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    return TRUE;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen}
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainenstatic const char *const *
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainenheaders_merge(pool_t pool, const char *const *h1, const char *const *h2)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen{
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    ARRAY_TYPE(const_string) headers;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    const char *value;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    unsigned int i;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    p_array_init(&headers, pool, 16);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (h1 != NULL) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        for (i = 0; h1[i] != NULL; i++) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            value = p_strdup(pool, h1[i]);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            array_append(&headers, &value, 1);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (h2 != NULL) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        for (i = 0; h2[i] != NULL; i++) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen            if (h1 == NULL || !str_array_icase_find(h1, h2[i])) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen                value = p_strdup(pool, h2[i]);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen                array_append(&headers, &value, 1);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen            }
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        }
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    array_append_zero(&headers);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    return array_idx(&headers, 0);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen}
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainenstatic int
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainenimapc_mail_send_fetch(struct mail *_mail, enum mail_fetch_field fields,
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen              const char *const *headers)
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen{
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    struct imapc_mail *mail = (struct imapc_mail *)_mail;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    struct imapc_mailbox *mbox = (struct imapc_mailbox *)_mail->box;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    struct imapc_command *cmd;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    struct mail_index_view *view;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    string_t *str;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    uint32_t seq;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    unsigned int i;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    if (_mail->lookup_abort != MAIL_LOOKUP_ABORT_NEVER)
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        return -1;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    /* drop any fields that we may already be fetching currently */
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    fields &= ~mail->fetching_fields;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    if (headers_have_subset(mail->fetching_headers, headers))
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        headers = NULL;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if (fields == 0 && headers == NULL)
ba886767d3817d210b20e1d42983078d189fb13cTimo Sirainen        return 0;
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen
ba886767d3817d210b20e1d42983078d189fb13cTimo Sirainen    if (!_mail->saving) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        /* if we already know that the mail is expunged,
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen           don't try to FETCH it */
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        view = mbox->delayed_sync_view != NULL ?
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            mbox->delayed_sync_view : mbox->box.view;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        if (!mail_index_lookup_seq(view, _mail->uid, &seq) ||
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            mail_index_is_expunged(view, seq)) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            mail_set_expunged(_mail);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            return -1;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        }
2766f1de8141c09767a959d2d2c3065c5a300bf0Timo Sirainen    } else if (mbox->client_box == NULL) {
2766f1de8141c09767a959d2d2c3065c5a300bf0Timo Sirainen        /* opened as save-only. we'll need to fetch the mail,
2766f1de8141c09767a959d2d2c3065c5a300bf0Timo Sirainen           so actually SELECT/EXAMINE the mailbox */
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        i_assert(mbox->box.opened);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        if (imapc_mailbox_select(mbox) < 0)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            return -1;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if ((fields & MAIL_FETCH_STREAM_BODY) != 0)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        fields |= MAIL_FETCH_STREAM_HEADER;
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    str = t_str_new(64);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    str_printfa(str, "UID FETCH %u (", _mail->uid);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if ((fields & MAIL_FETCH_RECEIVED_DATE) != 0)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        str_append(str, "INTERNALDATE ");
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    if ((fields & MAIL_FETCH_PHYSICAL_SIZE) != 0)
ba886767d3817d210b20e1d42983078d189fb13cTimo Sirainen        str_append(str, "RFC822.SIZE ");
ba886767d3817d210b20e1d42983078d189fb13cTimo Sirainen    if ((fields & MAIL_FETCH_GUID) != 0) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        str_append(str, mbox->guid_fetch_field_name);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        str_append_c(str, ' ');
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen    }
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    if ((fields & MAIL_FETCH_STREAM_BODY) != 0)
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        str_append(str, "BODY.PEEK[] ");
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    else if ((fields & MAIL_FETCH_STREAM_HEADER) != 0)
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        str_append(str, "BODY.PEEK[HEADER] ");
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen    else if (headers != NULL) {
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        mail->fetching_headers =
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            headers_merge(mail->imail.mail.pool, headers,
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen                      mail->fetching_headers);
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        str_append(str, "BODY.PEEK[HEADER.FIELDS (");
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen        for (i = 0; mail->fetching_headers[i] != NULL; i++) {
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            if (i > 0)
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen                str_append_c(str, ' ');
c59b9c273b41f7bcf51f6803110b67813879ff05Timo Sirainen            imap_append_astring(str, mail->fetching_headers[i]);
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        }
c33d3f93abf8392fdc60e12bea41ffd12cc85a8dTimo Sirainen        str_append(str, ")] ");
        mail->header_list_fetched = FALSE;
    }
    str_truncate(str, str_len(str)-1);
    str_append_c(str, ')');

    pool_ref(mail->imail.mail.pool);
    mail->fetching_fields |= fields;
    if (mail->fetch_count++ == 0)
        array_append(&mbox->fetch_mails, &mail, 1);

    cmd = imapc_client_mailbox_cmd(mbox->client_box,
                       imapc_mail_prefetch_callback, mail);
    imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
    imapc_command_send(cmd, str_c(str));
    mail->imail.data.prefetch_sent = TRUE;
    return 0;
}

static void imapc_mail_cache_get(struct imapc_mail *mail,
                 struct imapc_mail_cache *cache)
{
    if (mail->body_fetched)
        return;

    if (cache->fd != -1) {
        mail->fd = cache->fd;
        mail->imail.data.stream =
            i_stream_create_fd(mail->fd, 0, FALSE);
        cache->fd = -1;
    } else if (cache->buf != NULL) {
        mail->body = cache->buf;
        mail->imail.data.stream =
            i_stream_create_from_data(mail->body->data,
                          mail->body->used);
        cache->buf = NULL;
    } else {
        return;
    }
    mail->body_fetched = TRUE;
    imapc_mail_init_stream(mail, TRUE);
}

bool imapc_mail_prefetch(struct mail *_mail)
{
    struct imapc_mail *mail = (struct imapc_mail *)_mail;
    struct imapc_mailbox *mbox = (struct imapc_mailbox *)_mail->box;
    struct index_mail_data *data = &mail->imail.data;
    enum mail_fetch_field fields = 0;

    if (mbox->prev_mail_cache.uid == _mail->uid)
        imapc_mail_cache_get(mail, &mbox->prev_mail_cache);

    if ((data->wanted_fields & MAIL_FETCH_RECEIVED_DATE) != 0 &&
        data->received_date == (time_t)-1)
        fields |= MAIL_FETCH_RECEIVED_DATE;
    if ((data->wanted_fields & MAIL_FETCH_PHYSICAL_SIZE) != 0 &&
        data->physical_size == (uoff_t)-1 &&
        IMAPC_BOX_HAS_FEATURE(mbox, IMAPC_FEATURE_RFC822_SIZE))
        fields |= MAIL_FETCH_PHYSICAL_SIZE;
    if ((data->wanted_fields & MAIL_FETCH_GUID) != 0 &&
        data->guid == NULL && mbox->guid_fetch_field_name != NULL)
        fields |= MAIL_FETCH_GUID;

    if (data->stream == NULL && data->access_part != 0) {
        if ((data->access_part & (READ_BODY | PARSE_BODY)) != 0)
            fields |= MAIL_FETCH_STREAM_BODY;
        else
            fields |= MAIL_FETCH_STREAM_HEADER;
    }
    if (fields != 0) T_BEGIN {
        (void)imapc_mail_send_fetch(_mail, fields,
                        data->wanted_headers == NULL ? NULL :
                        data->wanted_headers->name);
    } T_END;
    return !mail->imail.data.prefetch_sent;
}

static bool
imapc_mail_have_fields(struct imapc_mail *imail, enum mail_fetch_field fields)
{
    if ((fields & MAIL_FETCH_RECEIVED_DATE) != 0) {
        if (imail->imail.data.received_date == (time_t)-1)
            return FALSE;
        fields &= ~MAIL_FETCH_RECEIVED_DATE;
    }
    if ((fields & MAIL_FETCH_PHYSICAL_SIZE) != 0) {
        if (imail->imail.data.physical_size == (uoff_t)-1)
            return FALSE;
        fields &= ~MAIL_FETCH_PHYSICAL_SIZE;
    }
    if ((fields & MAIL_FETCH_GUID) != 0) {
        if (imail->imail.data.guid == NULL)
            return FALSE;
        fields &= ~MAIL_FETCH_GUID;
    }
    if ((fields & (MAIL_FETCH_STREAM_HEADER |
               MAIL_FETCH_STREAM_BODY)) != 0) {
        if (imail->imail.data.stream == NULL)
            return FALSE;
        fields &= ~(MAIL_FETCH_STREAM_HEADER | MAIL_FETCH_STREAM_BODY);
    }
    i_assert(fields == 0);
    return TRUE;
}

int imapc_mail_fetch(struct mail *_mail, enum mail_fetch_field fields,
             const char *const *headers)
{
    struct imapc_mail *imail = (struct imapc_mail *)_mail;
    struct imapc_mailbox *mbox =
        (struct imapc_mailbox *)_mail->box;
    int ret;

    if ((fields & MAIL_FETCH_GUID) != 0 &&
        mbox->guid_fetch_field_name == NULL) {
        mail_storage_set_error(_mail->box->storage,
            MAIL_ERROR_NOTPOSSIBLE,
            "Message GUID not available in this server");
        return -1;
    }

    T_BEGIN {
        ret = imapc_mail_send_fetch(_mail, fields, headers);
    } T_END;
    if (ret < 0)
        return -1;

    /* we'll continue waiting until we've got all the fields we wanted,
       or until all FETCH replies have been received (i.e. some FETCHes
       failed) */
    while (imail->fetch_count > 0 &&
           (!imapc_mail_have_fields(imail, fields) ||
        !imail->header_list_fetched))
        imapc_storage_run(mbox->storage);
    return 0;
}

static bool imapc_find_lfile_arg(const struct imapc_untagged_reply *reply,
                 const struct imap_arg *arg, int *fd_r)
{
    const struct imap_arg *list;
    unsigned int i, count;

    for (i = 0; i < reply->file_args_count; i++) {
        const struct imapc_arg_file *farg = &reply->file_args[i];

        if (farg->parent_arg == arg->parent &&
            imap_arg_get_list_full(arg->parent, &list, &count) &&
            farg->list_idx < count && &list[farg->list_idx] == arg) {
            *fd_r = farg->fd;
            return TRUE;
        }
    }
    return FALSE;
}

static void imapc_stream_filter(struct istream **input)
{
    static const char *imapc_hide_headers[] = {
        /* Added by MS Exchange 2010 when \Flagged flag is set.
           This violates IMAP guarantee of messages being immutable. */
        "X-Message-Flag"
    };
    struct istream *filter_input;

    filter_input = i_stream_create_header_filter(*input,
        HEADER_FILTER_EXCLUDE,
        imapc_hide_headers, N_ELEMENTS(imapc_hide_headers),
        *null_header_filter_callback, (void *)NULL);
    i_stream_unref(input);
    *input = filter_input;
}

void imapc_mail_init_stream(struct imapc_mail *mail, bool have_body)
{
    struct index_mail *imail = &mail->imail;
    struct mail *_mail = &imail->mail.mail;
    struct istream *input;
    uoff_t size;
    int ret;

    i_stream_set_name(imail->data.stream,
              t_strdup_printf("imapc mail uid=%u", _mail->uid));
    index_mail_set_read_buffer_size(_mail, imail->data.stream);

    imapc_stream_filter(&imail->data.stream);
    if (imail->mail.v.istream_opened != NULL) {
        if (imail->mail.v.istream_opened(_mail,
                         &imail->data.stream) < 0) {
            index_mail_close_streams(imail);
            return;
        }
    } else if (have_body) {
        ret = i_stream_get_size(imail->data.stream, TRUE, &size);
        if (ret < 0) {
            index_mail_close_streams(imail);
            return;
        }
        i_assert(ret != 0);
        imail->data.physical_size = size;
        /* we'll assume that the remote server is working properly and
           sending CRLF linefeeds */
        imail->data.virtual_size = size;
    }

    imail->data.stream_has_only_header = !have_body;
    if (index_mail_init_stream(imail, NULL, NULL, &input) < 0)
        index_mail_close_streams(imail);
}

static void
imapc_fetch_stream(struct imapc_mail *mail,
           const struct imapc_untagged_reply *reply,
           const struct imap_arg *arg, bool body)
{
    struct index_mail *imail = &mail->imail;
    const char *value;
    int fd;

    if (imail->data.stream != NULL) {
        if (!body)
            return;
        /* maybe the existing stream has no body. replace it. */
        index_mail_close_streams(imail);
        if (mail->fd != -1) {
            if (close(mail->fd) < 0)
                i_error("close(imapc mail) failed: %m");
            mail->fd = -1;
        }
    }

    if (arg->type == IMAP_ARG_LITERAL_SIZE) {
        if (!imapc_find_lfile_arg(reply, arg, &fd))
            return;
        if ((fd = dup(fd)) == -1) {
            i_error("dup() failed: %m");
            return;
        }
        mail->fd = fd;
        imail->data.stream = i_stream_create_fd(fd, 0, FALSE);
    } else {
        if (!imap_arg_get_nstring(arg, &value))
            return;
        if (value == NULL) {
            mail_set_expunged(&imail->mail.mail);
            return;
        }
        if (mail->body == NULL) {
            mail->body = buffer_create_dynamic(default_pool,
                               arg->str_len + 1);
        }
        buffer_set_used_size(mail->body, 0);
        buffer_append(mail->body, value, arg->str_len);
        imail->data.stream = i_stream_create_from_data(mail->body->data,
                                   mail->body->used);
    }
    mail->body_fetched = body;

    imapc_mail_init_stream(mail, body);
}

static void
imapc_fetch_header_stream(struct imapc_mail *mail,
              const struct imapc_untagged_reply *reply,
              const struct imap_arg *args)
{
    const enum message_header_parser_flags hdr_parser_flags =
        MESSAGE_HEADER_PARSER_FLAG_SKIP_INITIAL_LWSP |
        MESSAGE_HEADER_PARSER_FLAG_DROP_CR;
    const struct imap_arg *hdr_list;
    struct mailbox_header_lookup_ctx *headers_ctx;
    struct message_header_parser_ctx *parser;
    struct message_header_line *hdr;
    struct istream *input;
    ARRAY_TYPE(const_string) hdr_arr;
    const char *value;
    int ret, fd;

    if (!imap_arg_get_list(args, &hdr_list))
        return;
    if (!imap_arg_atom_equals(args+1, "]"))
        return;
    args += 2;

    /* see if this is reply to the latest headers list request
       (parse it even if it's not) */
    t_array_init(&hdr_arr, 16);
    while (imap_arg_get_astring(hdr_list, &value)) {
        array_append(&hdr_arr, &value, 1);
        hdr_list++;
    }
    if (hdr_list->type != IMAP_ARG_EOL)
        return;
    array_append_zero(&hdr_arr);

    if (headers_have_subset(array_idx(&hdr_arr, 0), mail->fetching_headers))
        mail->header_list_fetched = TRUE;

    if (args->type == IMAP_ARG_LITERAL_SIZE) {
        if (!imapc_find_lfile_arg(reply, args, &fd))
            return;
        input = i_stream_create_fd(fd, 0, FALSE);
    } else {
        if (!imap_arg_get_nstring(args, &value))
            return;
        if (value == NULL) {
            mail_set_expunged(&mail->imail.mail.mail);
            return;
        }
        input = i_stream_create_from_data(value, args->str_len);
    }

    headers_ctx = mailbox_header_lookup_init(mail->imail.mail.mail.box,
                         array_idx(&hdr_arr, 0));
    index_mail_parse_header_init(&mail->imail, headers_ctx);

    parser = message_parse_header_init(input, NULL, hdr_parser_flags);
    while ((ret = message_parse_header_next(parser, &hdr)) > 0)
        index_mail_parse_header(NULL, hdr, &mail->imail);
    i_assert(ret != 0);
    index_mail_parse_header(NULL, NULL, &mail->imail);
    message_parse_header_deinit(&parser);

    mailbox_header_lookup_unref(&headers_ctx);
    i_stream_destroy(&input);
}

void imapc_mail_fetch_update(struct imapc_mail *mail,
                 const struct imapc_untagged_reply *reply,
                 const struct imap_arg *args)
{
    struct imapc_mailbox *mbox =
        (struct imapc_mailbox *)mail->imail.mail.mail.box;
    const char *key, *value;
    unsigned int i;
    uoff_t size;
    time_t t;
    int tz;
    bool match = FALSE;

    for (i = 0; args[i].type != IMAP_ARG_EOL; i += 2) {
        if (!imap_arg_get_atom(&args[i], &key) ||
            args[i+1].type == IMAP_ARG_EOL)
            break;

        if (strcasecmp(key, "BODY[]") == 0) {
            imapc_fetch_stream(mail, reply, &args[i+1], TRUE);
            match = TRUE;
        } else if (strcasecmp(key, "BODY[HEADER]") == 0) {
            imapc_fetch_stream(mail, reply, &args[i+1], FALSE);
            match = TRUE;
        } else if (strcasecmp(key, "BODY[HEADER.FIELDS") == 0) {
            imapc_fetch_header_stream(mail, reply, &args[i+1]);
            match = TRUE;
        } else if (strcasecmp(key, "INTERNALDATE") == 0) {
            if (imap_arg_get_astring(&args[i+1], &value) &&
                imap_parse_datetime(value, &t, &tz))
                mail->imail.data.received_date = t;
            match = TRUE;
        } else if (strcasecmp(key, "RFC822.SIZE") == 0) {
            if (imap_arg_get_atom(&args[i+1], &value) &&
                str_to_uoff(value, &size) == 0 &&
                IMAPC_BOX_HAS_FEATURE(mbox, IMAPC_FEATURE_RFC822_SIZE))
                mail->imail.data.physical_size = size;
            match = TRUE;
        } else if (strcasecmp(key, "X-GM-MSGID") == 0 ||
               strcasecmp(key, "X-GUID") == 0) {
            if (imap_arg_get_astring(&args[i+1], &value)) {
                mail->imail.data.guid =
                    p_strdup(mail->imail.mail.pool, value);
            }
            match = TRUE;
        }
    }
    if (!match) {
        /* this is only a FETCH FLAGS update for the wanted mail */
    } else {
        imapc_client_stop(mbox->storage->client->client);
    }
}