src/lib-storage/mail-search.c

	mail-search.c revision d549ec5d174279916518b5490cd21baeda38dedf
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen/* Copyright (c) 2002-2013 Dovecot authors, see the included COPYING file */
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen#include "lib.h"
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen#include "array.h"
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen#include "imap-match.h"
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen#include "mail-index.h"
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen#include "mail-storage.h"
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen#include "mail-namespace.h"
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen#include "mail-search-build.h"
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen#include "mail-search.h"
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainenstatic struct mail_search_arg *
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainenmail_search_arg_dup(pool_t pool, const struct mail_search_arg *arg);
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainenstatic bool mail_search_arg_equals(const struct mail_search_arg *arg1,
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen                   const struct mail_search_arg *arg2);
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainenstatic void
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainenmailbox_uidset_change(struct mail_search_arg *arg, struct mailbox *box,
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen              const ARRAY_TYPE(seq_range) *search_saved_uidset)
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen{
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen    struct seq_range *uids;
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen    unsigned int i, count;
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen    uint32_t seq1, seq2;
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen    if (arg->value.str != NULL && strcmp(arg->value.str, "$") == 0) {
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen        /* SEARCHRES: Replace with saved uidset */
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen        array_clear(&arg->value.seqset);
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen        if (search_saved_uidset == NULL ||
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen            !array_is_created(search_saved_uidset))
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen            return;
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen        array_append_array(&arg->value.seqset, search_saved_uidset);
f6ae9ae80a1fcf6c8f45ab759f0074caaa66c9c8Timo Sirainen        return;
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen    }
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen    arg->type = SEARCH_SEQSET;
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen    /* make a copy of the UIDs */
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen    count = array_count(&arg->value.seqset);
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen    if (count == 0) {
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen        /* empty set, keep it */
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen        return;
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen    }
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen    uids = t_new(struct seq_range, count);
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen    memcpy(uids, array_idx(&arg->value.seqset, 0), sizeof(*uids) * count);
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen    /* put them back to the range as sequences */
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen    array_clear(&arg->value.seqset);
10972f2a15f5538860fcc1d4adda227d59d2d757Timo Sirainen    for (i = 0; i < count; i++) {
4ca2ccd50ad25260865f561e4ebf36899d7fe966Timo Sirainen        mailbox_get_seq_range(box, uids[i].seq1, uids[i].seq2,
bb869cc24b24a8df84a43154c628785d6aee784cTimo Sirainen                      &seq1, &seq2);
bb869cc24b24a8df84a43154c628785d6aee784cTimo Sirainen        if (seq1 != 0) {
4ca2ccd50ad25260865f561e4ebf36899d7fe966Timo Sirainen            seq_range_array_add_range(&arg->value.seqset,
e0ba54c7f985fc403b41c6e36d6a7f44908b23f0Timo Sirainen                          seq1, seq2);
        }
        if (uids[i].seq2 == (uint32_t)-1) {
            /* make sure the last message is in the range */
            mailbox_get_seq_range(box, 1, (uint32_t)-1,
                          &seq1, &seq2);
            seq_range_array_add(&arg->value.seqset, seq2);
        }
    }
}

static void
mail_search_args_init_sub(struct mail_search_args *args,
              struct mail_search_arg *arg,
              bool change_uidsets,
              const ARRAY_TYPE(seq_range) *search_saved_uidset)
{
    struct mail_search_args *thread_args;
    const char *keywords[2];

    for (; arg != NULL; arg = arg->next) {
        switch (arg->type) {
        case SEARCH_UIDSET:
            if (change_uidsets) T_BEGIN {
                mailbox_uidset_change(arg, args->box,
                              search_saved_uidset);
            } T_END;
            break;
        case SEARCH_MODSEQ:
            if (arg->value.str == NULL)
                break;
            /* modseq with keyword */
        case SEARCH_KEYWORDS:
            keywords[0] = arg->value.str;
            keywords[1] = NULL;

            i_assert(arg->value.keywords == NULL);
            arg->value.keywords =
                mailbox_keywords_create_valid(args->box,
                                  keywords);
            break;

        case SEARCH_MAILBOX_GLOB: {
            struct mail_namespace *ns =
                mailbox_get_namespace(args->box);

            arg->value.mailbox_glob =
                imap_match_init(default_pool, arg->value.str,
                        TRUE, mail_namespace_get_sep(ns));
            break;
        }
        case SEARCH_INTHREAD:
            thread_args = arg->value.search_args;
            if (thread_args == NULL) {
                arg->value.search_args = thread_args =
                    p_new(args->pool,
                          struct mail_search_args, 1);
                thread_args->pool = args->pool;
                thread_args->args = arg->value.subargs;
                thread_args->simplified = TRUE;
                /* simplification should have unnested all
                   inthreads, so we'll assume that
                   have_inthreads=FALSE */
            }
            thread_args->refcount++;
            thread_args->box = args->box;
            /* fall through */
        case SEARCH_SUB:
        case SEARCH_OR:
            mail_search_args_init_sub(args, arg->value.subargs,
                          change_uidsets,
                          search_saved_uidset);
            break;
        default:
            break;
        }
    }
}

void mail_search_args_init(struct mail_search_args *args,
               struct mailbox *box, bool change_uidsets,
               const ARRAY_TYPE(seq_range) *search_saved_uidset)
{
    i_assert(args->init_refcount <= args->refcount);

    if (args->init_refcount++ > 0) {
        i_assert(args->box == box);
        return;
    }

    args->box = box;
    if (!args->simplified)
        mail_search_args_simplify(args);
    mail_search_args_init_sub(args, args->args, change_uidsets,
                  search_saved_uidset);
}

static void mail_search_args_deinit_sub(struct mail_search_args *args,
                    struct mail_search_arg *arg)
{
    for (; arg != NULL; arg = arg->next) {
        switch (arg->type) {
        case SEARCH_MODSEQ:
        case SEARCH_KEYWORDS:
            if (arg->value.keywords == NULL)
                break;
            mailbox_keywords_unref(&arg->value.keywords);
            break;
        case SEARCH_MAILBOX_GLOB:
            if (arg->value.mailbox_glob == NULL)
                break;

            imap_match_deinit(&arg->value.mailbox_glob);
            break;
        case SEARCH_INTHREAD:
            i_assert(arg->value.search_args->refcount > 0);
            if (args->refcount == 0 &&
                arg->value.search_result != NULL) {
                mailbox_search_result_free(
                    &arg->value.search_result);
            }
            arg->value.search_args->refcount--;
            arg->value.search_args->box = NULL;
            /* fall through */
        case SEARCH_SUB:
        case SEARCH_OR:
            mail_search_args_deinit_sub(args, arg->value.subargs);
            break;
        default:
            break;
        }
    }
}

void mail_search_args_deinit(struct mail_search_args *args)
{
    if (--args->init_refcount > 0)
        return;

    mail_search_args_deinit_sub(args, args->args);
    args->box = NULL;
}

static void mail_search_args_seq2uid_sub(struct mail_search_args *args,
                     struct mail_search_arg *arg,
                     ARRAY_TYPE(seq_range) *uids)
{
    for (; arg != NULL; arg = arg->next) {
        switch (arg->type) {
        case SEARCH_SEQSET:
            array_clear(uids);
            mailbox_get_uid_range(args->box,
                          &arg->value.seqset, uids);

            /* replace sequences with UIDs in the existing array.
               this way it's possible to switch between uidsets and
               seqsets constantly without leaking memory */
            arg->type = SEARCH_UIDSET;
            array_clear(&arg->value.seqset);
            array_append_array(&arg->value.seqset, uids);
            break;
        case SEARCH_SUB:
        case SEARCH_OR:
        case SEARCH_INTHREAD:
            mail_search_args_seq2uid_sub(args, arg->value.subargs,
                             uids);
            break;
        default:
            break;
        }
    }
}

void mail_search_args_seq2uid(struct mail_search_args *args)
{
    T_BEGIN {
        ARRAY_TYPE(seq_range) uids;

        t_array_init(&uids, 128);
        mail_search_args_seq2uid_sub(args, args->args, &uids);
    } T_END;
}

void mail_search_args_ref(struct mail_search_args *args)
{
    i_assert(args->refcount > 0);

    args->refcount++;
}

void mail_search_args_unref(struct mail_search_args **_args)
{
    struct mail_search_args *args = *_args;

    i_assert(args->refcount > 0);

    *_args = NULL;
    if (--args->refcount > 0) {
        i_assert(args->init_refcount <= args->refcount);
        return;
    }
    i_assert(args->init_refcount <= 1);
    if (args->init_refcount == 1)
        mail_search_args_deinit(args);
    pool_unref(&args->pool);
}

static struct mail_search_arg *
mail_search_arg_dup_one(pool_t pool, const struct mail_search_arg *arg)
{
    struct mail_search_arg *new_arg;

    new_arg = p_new(pool, struct mail_search_arg, 1);
    new_arg->type = arg->type;
    new_arg->match_not = arg->match_not;
    new_arg->match_always = arg->match_always;
    new_arg->nonmatch_always = arg->nonmatch_always;
    new_arg->value.search_flags = arg->value.search_flags;

    switch (arg->type) {
    case SEARCH_INTHREAD:
        new_arg->value.thread_type = arg->value.thread_type;
        /* fall through */
    case SEARCH_OR:
    case SEARCH_SUB:
        new_arg->value.subargs =
            mail_search_arg_dup(pool, arg->value.subargs);
        break;
    case SEARCH_ALL:
        break;
    case SEARCH_SEQSET:
    case SEARCH_UIDSET:
        p_array_init(&new_arg->value.seqset, pool,
                 array_count(&arg->value.seqset));
        array_append_array(&new_arg->value.seqset, &arg->value.seqset);
        break;
    case SEARCH_FLAGS:
        new_arg->value.flags = arg->value.flags;
        break;
    case SEARCH_BEFORE:
    case SEARCH_ON:
    case SEARCH_SINCE:
        new_arg->value.time = arg->value.time;
        new_arg->value.date_type = arg->value.date_type;
        break;
    case SEARCH_SMALLER:
    case SEARCH_LARGER:
        new_arg->value.size = arg->value.size;
        break;
    case SEARCH_HEADER:
    case SEARCH_HEADER_ADDRESS:
    case SEARCH_HEADER_COMPRESS_LWSP:
        new_arg->hdr_field_name = p_strdup(pool, arg->hdr_field_name);
        /* fall through */
    case SEARCH_KEYWORDS:
    case SEARCH_BODY:
    case SEARCH_TEXT:
    case SEARCH_GUID:
    case SEARCH_MAILBOX:
    case SEARCH_MAILBOX_GUID:
    case SEARCH_MAILBOX_GLOB:
        new_arg->value.str = p_strdup(pool, arg->value.str);
        break;
    case SEARCH_MODSEQ:
        new_arg->value.modseq =
            p_new(pool, struct mail_search_modseq, 1);
        *new_arg->value.modseq = *arg->value.modseq;
        break;
    }
    return new_arg;
}

static struct mail_search_arg *
mail_search_arg_dup(pool_t pool, const struct mail_search_arg *arg)
{
    struct mail_search_arg *new_arg = NULL, **dest = &new_arg;

    for (; arg != NULL; arg = arg->next) {
        *dest = mail_search_arg_dup_one(pool, arg);
        dest = &(*dest)->next;
    }
    return new_arg;
}

struct mail_search_args *
mail_search_args_dup(const struct mail_search_args *args)
{
    struct mail_search_args *new_args;

    new_args = mail_search_build_init();
    new_args->simplified = args->simplified;
    new_args->have_inthreads = args->have_inthreads;
    new_args->args = mail_search_arg_dup(new_args->pool, args->args);
    return new_args;
}

void mail_search_args_reset(struct mail_search_arg *args, bool full_reset)
{
    while (args != NULL) {
        if (args->type == SEARCH_OR || args->type == SEARCH_SUB)
            mail_search_args_reset(args->value.subargs, full_reset);

        if (args->match_always) {
            if (!full_reset)
                args->result = 1;
            else {
                args->match_always = FALSE;
                args->result = -1;
            }
        } else if (args->nonmatch_always) {
            if (!full_reset)
                args->result = 0;
            else {
                args->nonmatch_always = FALSE;
                args->result = -1;
            }
        } else {
            args->result = -1;
        }

        args = args->next;
    }
}

static void search_arg_foreach(struct mail_search_arg *arg,
                   mail_search_foreach_callback_t *callback,
                   void *context)
{
    struct mail_search_arg *subarg;

    if (arg->result != -1)
        return;

    if (arg->type == SEARCH_SUB) {
        /* sublist of conditions */
        i_assert(arg->value.subargs != NULL);

        arg->result = 1;
        subarg = arg->value.subargs;
        while (subarg != NULL) {
            if (subarg->result == -1)
                search_arg_foreach(subarg, callback, context);

            if (subarg->result == -1)
                arg->result = -1;
            else if (subarg->result == 0) {
                /* didn't match */
                arg->result = 0;
                break;
            }

            subarg = subarg->next;
        }
        if (arg->match_not && arg->result != -1)
            arg->result = !arg->result;
    } else if (arg->type == SEARCH_OR) {
        /* OR-list of conditions */
        i_assert(arg->value.subargs != NULL);

        subarg = arg->value.subargs;
        arg->result = 0;
        while (subarg != NULL) {
            if (subarg->result == -1)
                search_arg_foreach(subarg, callback, context);

            if (subarg->result == -1)
                arg->result = -1;
            else if (subarg->result > 0) {
                /* matched */
                arg->result = 1;
                break;
            }

            subarg = subarg->next;
        }
        if (arg->match_not && arg->result != -1)
            arg->result = !arg->result;
    } else {
        /* just a single condition */
        callback(arg, context);
    }
}

#undef mail_search_args_foreach
int mail_search_args_foreach(struct mail_search_arg *args,
                 mail_search_foreach_callback_t *callback,
                 void *context)
{
    int result;

    result = 1;
    for (; args != NULL; args = args->next) {
        search_arg_foreach(args, callback, context);

        if (args->result == 0) {
            /* didn't match */
            return 0;
        }

        if (args->result == -1)
            result = -1;
    }

    return result;
}

static void
search_arg_analyze(struct mail_search_arg *arg, buffer_t *headers,
           bool *have_body, bool *have_text)
{
    static const char *date_hdr = "Date";
    struct mail_search_arg *subarg;

    if (arg->result != -1)
        return;

    switch (arg->type) {
    case SEARCH_OR:
    case SEARCH_SUB:
        subarg = arg->value.subargs;
        while (subarg != NULL) {
            if (subarg->result == -1) {
                search_arg_analyze(subarg, headers,
                           have_body, have_text);
            }

            subarg = subarg->next;
        }
        break;
    case SEARCH_BEFORE:
    case SEARCH_ON:
    case SEARCH_SINCE:
        if (arg->value.date_type == MAIL_SEARCH_DATE_TYPE_SENT)
            buffer_append(headers, &date_hdr, sizeof(const char *));
        break;
    case SEARCH_HEADER:
    case SEARCH_HEADER_ADDRESS:
    case SEARCH_HEADER_COMPRESS_LWSP:
        buffer_append(headers, &arg->hdr_field_name,
                  sizeof(const char *));
        break;
    case SEARCH_BODY:
        *have_body = TRUE;
        break;
    case SEARCH_TEXT:
        *have_text = TRUE;
        *have_body = TRUE;
        break;
    default:
        break;
    }
}

const char *const *
mail_search_args_analyze(struct mail_search_arg *args,
             bool *have_headers, bool *have_body)
{
    const char *null = NULL;
    buffer_t *headers;
    bool have_text;

    *have_headers = *have_body = have_text = FALSE;

    headers = buffer_create_dynamic(pool_datastack_create(), 128);
    for (; args != NULL; args = args->next)
        search_arg_analyze(args, headers, have_body, &have_text);

    *have_headers = have_text || headers->used != 0;

    if (headers->used == 0 || have_text)
        return NULL;

    buffer_append(headers, &null, sizeof(const char *));
    return buffer_get_data(headers, NULL);
}

static bool
mail_search_args_match_mailbox_arg(const struct mail_search_arg *arg,
                   const char *vname, char sep)
{
    const struct mail_search_arg *subarg;
    bool ret;

    switch (arg->type) {
    case SEARCH_OR:
        subarg = arg->value.subargs;
        for (; subarg != NULL; subarg = subarg->next) {
            if (mail_search_args_match_mailbox_arg(subarg,
                                   vname, sep))
                return TRUE;
        }
        return FALSE;
    case SEARCH_SUB:
    case SEARCH_INTHREAD:
        subarg = arg->value.subargs;
        for (; subarg != NULL; subarg = subarg->next) {
            if (!mail_search_args_match_mailbox_arg(subarg,
                                vname, sep))
                return FALSE;
        }
        return TRUE;
    case SEARCH_MAILBOX:
        ret = strcmp(arg->value.str, vname) == 0;
        return ret != arg->match_not;
    case SEARCH_MAILBOX_GLOB: {
        T_BEGIN {
            struct imap_match_glob *glob;

            glob = imap_match_init(pool_datastack_create(),
                           arg->value.str, TRUE, sep);
            ret = imap_match(glob, vname) == IMAP_MATCH_YES;
        } T_END;
        return ret != arg->match_not;
    }
    default:
        break;
    }
    return TRUE;
}

bool mail_search_args_match_mailbox(struct mail_search_args *args,
                    const char *vname, char sep)
{
    const struct mail_search_arg *arg;

    if (!args->simplified)
        mail_search_args_simplify(args);

    for (arg = args->args; arg != NULL; arg = arg->next) {
        if (!mail_search_args_match_mailbox_arg(arg, vname, sep))
            return FALSE;
    }
    return TRUE;
}

static void
mail_search_args_simplify_sub(struct mailbox *box,
                  struct mail_search_arg *args, bool parent_and)
{
    struct mail_search_arg *sub, *prev = NULL;
    struct mail_search_arg *prev_flags_arg, *prev_not_flags_arg;

    prev_flags_arg = prev_not_flags_arg = NULL;
    while (args != NULL) {
        if (args->match_not && (args->type == SEARCH_SUB ||
                    args->type == SEARCH_OR)) {
            /* neg(p and q and ..) == neg(p) or neg(q) or ..
               neg(p or q or ..) == neg(p) and neg(q) and .. */
            args->type = args->type == SEARCH_SUB ?
                SEARCH_OR : SEARCH_SUB;
            args->match_not = FALSE;
            sub = args->value.subargs;
            do {
                sub->match_not = !sub->match_not;
                sub = sub->next;
            } while (sub != NULL);
        }

        if ((args->type == SEARCH_SUB && parent_and) ||
            (args->type == SEARCH_OR && !parent_and) ||
            ((args->type == SEARCH_SUB || args->type == SEARCH_OR) &&
             args->value.subargs->next == NULL)) {
            /* p and (q and ..) == p and q and ..
               p or (q or ..) == p or q or ..
               (p) = p */
            sub = args->value.subargs;
            for (; sub->next != NULL; sub = sub->next) ;
            sub->next = args->next;
            *args = *args->value.subargs;
            continue;
        }

        if (args->type == SEARCH_SUB ||
            args->type == SEARCH_OR ||
            args->type == SEARCH_INTHREAD) {
            mail_search_args_simplify_sub(box, args->value.subargs,
                              args->type != SEARCH_OR);
        }

        /* merge all flags arguments */
        if (args->type == SEARCH_FLAGS &&
            !args->match_not && parent_and) {
            if (prev_flags_arg == NULL)
                prev_flags_arg = args;
            else {
                prev_flags_arg->value.flags |=
                    args->value.flags;
                prev->next = args->next;
                args = args->next;
                continue;
            }
        } else if (args->type == SEARCH_FLAGS && args->match_not &&
               !parent_and) {
            if (prev_not_flags_arg == NULL)
                prev_not_flags_arg = args;
            else {
                prev_not_flags_arg->value.flags |=
                    args->value.flags;
                prev->next = args->next;
                args = args->next;
                continue;
            }
        }

        prev = args;
        args = args->next;
    }
}

static bool
mail_search_args_unnest_inthreads(struct mail_search_args *args,
                  struct mail_search_arg **argp,
                  bool parent_inthreads, bool parent_and)
{
    struct mail_search_arg *arg, *thread_arg, *or_arg;
    bool child_inthreads = FALSE, non_inthreads = FALSE;

    for (arg = *argp; arg != NULL; arg = arg->next) {
        switch (arg->type) {
        case SEARCH_SUB:
        case SEARCH_OR:
            if (!mail_search_args_unnest_inthreads(args,
                    &arg->value.subargs, parent_inthreads,
                    arg->type != SEARCH_OR)) {
                arg->result = 1;
                child_inthreads = TRUE;
            } else {
                arg->result = 0;
                non_inthreads = TRUE;
            }
            break;
        case SEARCH_INTHREAD:
            if (mail_search_args_unnest_inthreads(args,
                    &arg->value.subargs, TRUE, TRUE)) {
                /* children converted to SEARCH_INTHREADs */
                arg->type = SEARCH_SUB;
            }
            args->have_inthreads = TRUE;
            arg->result = 1;
            child_inthreads = TRUE;
            break;
        default:
            arg->result = 0;
            non_inthreads = TRUE;
            break;
        }
    }

    if (!parent_inthreads || !child_inthreads || !non_inthreads)
        return FALSE;

    /* put all non-INTHREADs under a single INTHREAD */
    thread_arg = p_new(args->pool, struct mail_search_arg, 1);
    thread_arg->type = SEARCH_INTHREAD;

    while (*argp != NULL) {
        arg = *argp;
        argp = &(*argp)->next;

        if (arg->result == 0) {
            /* not an INTHREAD or a SUB/OR with only INTHREADs */
            arg->next = thread_arg->value.subargs;
            thread_arg->value.subargs = arg;
        }
    }
    if (!parent_and) {
        /* We want to OR the args */
        or_arg = p_new(args->pool, struct mail_search_arg, 1);
        or_arg->type = SEARCH_OR;
        or_arg->value.subargs = thread_arg->value.subargs;
        thread_arg->value.subargs = or_arg;
    }
    return TRUE;
}

void mail_search_args_simplify(struct mail_search_args *args)
{
    args->simplified = TRUE;

    mail_search_args_simplify_sub(args->box, args->args, TRUE);
    if (mail_search_args_unnest_inthreads(args, &args->args,
                          FALSE, TRUE)) {
        /* we may have added some extra SUBs that could be dropped */
        mail_search_args_simplify_sub(args->box, args->args, TRUE);
    }
}

static bool mail_search_arg_one_equals(const struct mail_search_arg *arg1,
                       const struct mail_search_arg *arg2)
{
    if (arg1->type != arg2->type ||
        arg1->match_not != arg2->match_not)
        return FALSE;

    switch (arg1->type) {
    case SEARCH_OR:
    case SEARCH_SUB:
        return mail_search_arg_equals(arg1->value.subargs,
                          arg2->value.subargs);

    case SEARCH_ALL:
        return TRUE;
    case SEARCH_SEQSET:
        /* sequences may point to different messages at different times,
           never assume they match */
        return FALSE;
    case SEARCH_UIDSET:
        return array_cmp(&arg1->value.seqset, &arg2->value.seqset);

    case SEARCH_FLAGS:
        return arg1->value.flags == arg2->value.flags;
    case SEARCH_KEYWORDS:
        return strcasecmp(arg1->value.str, arg2->value.str);

    case SEARCH_BEFORE:
    case SEARCH_ON:
    case SEARCH_SINCE:
        return arg1->value.time == arg2->value.time &&
            arg1->value.date_type == arg2->value.date_type;

    case SEARCH_SMALLER:
    case SEARCH_LARGER:
        return arg1->value.size == arg2->value.size;

    case SEARCH_HEADER:
    case SEARCH_HEADER_ADDRESS:
    case SEARCH_HEADER_COMPRESS_LWSP:
        if (strcasecmp(arg1->hdr_field_name, arg2->hdr_field_name) != 0)
            return FALSE;
        /* fall through */
    case SEARCH_BODY:
    case SEARCH_TEXT:
    case SEARCH_GUID:
    case SEARCH_MAILBOX:
    case SEARCH_MAILBOX_GUID:
    case SEARCH_MAILBOX_GLOB:
        /* don't bother doing case-insensitive comparison. it must not
           be done for guid/mailbox, and for others we should support
           full i18n case-insensitivity (or the active comparator
           in future). */
        return strcmp(arg1->value.str, arg2->value.str) == 0;

    case SEARCH_MODSEQ: {
        const struct mail_search_modseq *m1 = arg1->value.modseq;
        const struct mail_search_modseq *m2 = arg2->value.modseq;

        return m1->modseq == m2->modseq &&
            m1->type == m2->type;
    }
    case SEARCH_INTHREAD:
        return mail_search_args_equal(arg1->value.search_args,
                          arg2->value.search_args);
    }
    i_unreached();
    return FALSE;
}

static bool mail_search_arg_equals(const struct mail_search_arg *arg1,
                   const struct mail_search_arg *arg2)
{
    while (arg1 != NULL && arg2 != NULL) {
        if (!mail_search_arg_one_equals(arg1, arg2))
            return FALSE;
        arg1 = arg1->next;
        arg2 = arg2->next;
    }
    return arg1 == NULL && arg2 == NULL;
}

bool mail_search_args_equal(const struct mail_search_args *args1,
                const struct mail_search_args *args2)
{
    i_assert(args1->simplified == args2->simplified);
    i_assert(args1->box == args2->box);

    return mail_search_arg_equals(args1->args, args2->args);
}

static void
mail_search_args_result_serialize_arg(const struct mail_search_arg *arg,
                      buffer_t *dest)
{
    const struct mail_search_arg *subarg;

    buffer_append_c(dest, arg->result < 0 ? 0xff : arg->result);

    switch (arg->type) {
    case SEARCH_OR:
    case SEARCH_SUB:
    case SEARCH_INTHREAD:
        subarg = arg->value.subargs;
        for (; subarg != NULL; subarg = subarg->next)
            mail_search_args_result_serialize_arg(subarg, dest);
    default:
        break;
    }
}

void mail_search_args_result_serialize(const struct mail_search_args *args,
                       buffer_t *dest)
{
    const struct mail_search_arg *arg;

    for (arg = args->args; arg != NULL; arg = arg->next)
        mail_search_args_result_serialize_arg(arg, dest);
}

static void
mail_search_args_result_deserialize_arg(struct mail_search_arg *arg,
                    const unsigned char **data,
                    size_t *size)
{
    struct mail_search_arg *subarg;

    i_assert(*size > 0);
    arg->result = **data == 0xff ? -1 : **data;
    *data += 1; *size -= 1;

    switch (arg->type) {
    case SEARCH_OR:
    case SEARCH_SUB:
    case SEARCH_INTHREAD:
        subarg = arg->value.subargs;
        for (; subarg != NULL; subarg = subarg->next) {
            mail_search_args_result_deserialize_arg(subarg,
                                data, size);
        }
    default:
        break;
    }
}

void mail_search_args_result_deserialize(struct mail_search_args *args,
                     const unsigned char *data, size_t size)
{
    struct mail_search_arg *arg;

    for (arg = args->args; arg != NULL; arg = arg->next)
        mail_search_args_result_deserialize_arg(arg, &data, &size);
}