/** @file
 * @brief Tests of closing databases.
 */
/* Copyright 2008,2009 Lemur Consulting Ltd
 * Copyright 2009,2012,2015,2023 Olly Betts
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see
 * <https://www.gnu.org/licenses/>.
 */

#include <config.h>

#include "api_closedb.h"

#include <xapian.h>

#include "safeunistd.h"

#include "apitest.h"
#include "testutils.h"

using namespace std;

#define COUNT_EXCEPTION(CODE, EXCEPTION) \
    try { \
        CODE; \
    } catch (const Xapian::EXCEPTION&) { \
        ++exception_count; \
    }

#define COUNT_CLOSED(CODE) COUNT_EXCEPTION(CODE, DatabaseClosedError)

// Iterators used by closedb1.
struct closedb1_iterators {
    Xapian::Database db;
    Xapian::Document doc1;
    Xapian::PostingIterator pl1;
    Xapian::PostingIterator pl2;
    Xapian::PostingIterator pl1end;
    Xapian::PostingIterator pl2end;
    Xapian::TermIterator tl1;
    Xapian::TermIterator tlend;
    Xapian::TermIterator atl1;
    Xapian::TermIterator atlend;
    Xapian::PositionIterator pil1;
    Xapian::PositionIterator pilend;

    void setup(Xapian::Database db_) {
        db = db_;

        // Set up the iterators for the test.
        pl1 = db.postlist_begin("paragraph");
        pl2 = db.postlist_begin("this");
        ++pl2;
        pl1end = db.postlist_end("paragraph");
        pl2end = db.postlist_end("this");
        tl1 = db.termlist_begin(1);
        tlend = db.termlist_end(1);
        atl1 = db.allterms_begin("t");
        atlend = db.allterms_end("t");
        pil1 = db.positionlist_begin(1, "paragraph");
        pilend = db.positionlist_end(1, "paragraph");
    }

    int perform() {
        int exception_count = 0;

        // Getting a document may throw.
        COUNT_CLOSED(
            doc1 = db.get_document(1);
            // Only do these if get_document() succeeded.
            COUNT_CLOSED(TEST_EQUAL(doc1.get_data().substr(0, 33),
                                    "This is a test document used with"));
            COUNT_CLOSED(doc1.termlist_begin());
        );

        // Causing the database to access its files raises the "database
        // closed" error.
        COUNT_CLOSED(db.postlist_begin("paragraph"));
        COUNT_CLOSED(db.get_document(1).get_value(1));
        COUNT_CLOSED(db.termlist_begin(1));
        COUNT_CLOSED(db.positionlist_begin(1, "paragraph"));
        COUNT_CLOSED(db.allterms_begin());
        COUNT_CLOSED(db.allterms_begin("p"));
        COUNT_CLOSED(db.get_termfreq("paragraph"));
        COUNT_CLOSED(db.get_collection_freq("paragraph"));
        COUNT_CLOSED(db.term_exists("paragraph"));
        COUNT_CLOSED(db.get_value_freq(1));
        COUNT_CLOSED(db.get_value_lower_bound(1));
        COUNT_CLOSED(db.get_value_upper_bound(1));
        COUNT_CLOSED(db.valuestream_begin(1));
        COUNT_CLOSED(db.get_doclength(1));
        COUNT_CLOSED(db.get_unique_terms(1));

        // Reopen raises the "database closed" error.
        COUNT_CLOSED(db.reopen());

        TEST_NOT_EQUAL(pl1, pl1end);
        TEST_NOT_EQUAL(pl2, pl2end);
        TEST_NOT_EQUAL(tl1, tlend);
        TEST_NOT_EQUAL(atl1, atlend);
        TEST_NOT_EQUAL(pil1, pilend);

        COUNT_CLOSED(db.postlist_begin("paragraph"));

        COUNT_CLOSED(TEST_EQUAL(*pl1, 1));
        COUNT_CLOSED(TEST_EQUAL(pl1.get_doclength(), 28));
        COUNT_CLOSED(TEST_EQUAL(pl1.get_unique_terms(), 21));

        COUNT_CLOSED(TEST_EQUAL(*pl2, 2));
        COUNT_CLOSED(TEST_EQUAL(pl2.get_doclength(), 81));
        COUNT_CLOSED(TEST_EQUAL(pl2.get_unique_terms(), 56));

        COUNT_CLOSED(TEST_EQUAL(*tl1, "a"));
        COUNT_CLOSED(TEST_EQUAL(tl1.get_wdf(), 2));
        COUNT_CLOSED(TEST_EQUAL(tl1.get_termfreq(), 3));

        COUNT_CLOSED(TEST_EQUAL(*atl1, "test"));
        COUNT_CLOSED(TEST_EQUAL(atl1.get_termfreq(), 1));

        COUNT_CLOSED(TEST_EQUAL(*pil1, 12));

        // Advancing the iterator may or may not raise an error, but if it
        // doesn't it must return the correct answers.
        COUNT_CLOSED(
            ++pl1;
            COUNT_CLOSED(TEST_EQUAL(*pl1, 2));
            COUNT_CLOSED(TEST_EQUAL(pl1.get_doclength(), 81));
            COUNT_CLOSED(TEST_EQUAL(pl1.get_unique_terms(), 56));
        );

        COUNT_CLOSED(
            ++pl2;
            COUNT_CLOSED(TEST_EQUAL(*pl2, 3));
            COUNT_CLOSED(TEST_EQUAL(pl2.get_doclength(), 15));
            COUNT_CLOSED(TEST_EQUAL(pl2.get_unique_terms(), 14));
        );

        COUNT_CLOSED(
            ++tl1;
            COUNT_CLOSED(TEST_EQUAL(*tl1, "api"));
            COUNT_CLOSED(TEST_EQUAL(tl1.get_wdf(), 1));
            COUNT_CLOSED(TEST_EQUAL(tl1.get_termfreq(), 1));
        );

        COUNT_CLOSED(
            ++atl1;
            COUNT_CLOSED(TEST_EQUAL(*atl1, "that"));
            COUNT_CLOSED(TEST_EQUAL(atl1.get_termfreq(), 2));
        );

        COUNT_CLOSED(
            ++pil1;
            COUNT_CLOSED(TEST_EQUAL(*pil1, 28));
        );

        return exception_count;
    }
};

// Test for closing a database
DEFINE_TESTCASE(closedb1, backend) {
    Xapian::Database db(get_database("apitest_simpledata"));
    closedb1_iterators iters;

    // Run the test, checking that we get no "closed" exceptions.
    iters.setup(db);
    int exception_count = iters.perform();
    TEST_EQUAL(exception_count, 0);

    // Setup for the next test.
    iters.setup(db);

    // Close the database.
    db.close();

    // Dup stdout to the fds which the database was using, to try to catch
    // issues with lingering references to closed fds (regression test for
    // early development versions of honey).
    vector<int> fds;
    for (int i = 0; i != 6; ++i) {
        fds.push_back(dup(1));
    }

    // Reopening a closed database should always raise DatabaseClosedError.
    TEST_EXCEPTION(Xapian::DatabaseClosedError, db.reopen());

    // Run the test again, checking that we get some "closed" exceptions.
    exception_count = iters.perform();
    TEST_NOT_EQUAL(exception_count, 0);

    // get_description() shouldn't throw an exception.  Actually do something
    // with the description, in case this method is marked as "pure" in the
    // future.
    TEST(!db.get_description().empty());

    // Calling close repeatedly is okay.
    db.close();

    for (int fd : fds) {
        close(fd);
    }
}

// Test closing a writable database, and that it drops the lock.
DEFINE_TESTCASE(closedb2, writable && path) {
    Xapian::WritableDatabase dbw1(get_named_writable_database("apitest_closedb2"));
    TEST_EXCEPTION(Xapian::DatabaseLockError,
                   Xapian::WritableDatabase db(get_named_writable_database_path("apitest_closedb2"),
                                               Xapian::DB_OPEN));
    dbw1.close();
    Xapian::WritableDatabase dbw2 = get_named_writable_database("apitest_closedb2");
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
               dbw1.postlist_begin("paragraph"));
    TEST_EQUAL(dbw2.postlist_begin("paragraph"), dbw2.postlist_end("paragraph"));
}

/// Check API methods which might either work or throw an exception.
DEFINE_TESTCASE(closedb3, backend) {
    Xapian::Database db(get_database("etext"));
    const string & uuid = db.get_uuid();
    db.close();
    try {
        TEST_EQUAL(db.get_uuid(), uuid);
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        TEST(db.has_positions());
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        TEST_EQUAL(db.get_doccount(), 566);
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        TEST_EQUAL(db.get_lastdocid(), 566);
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        TEST_REL(db.get_doclength_lower_bound(), <, db.get_avlength());
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        TEST_REL(db.get_doclength_upper_bound(), >, db.get_avlength());
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        TEST(db.get_wdf_upper_bound("king"));
    } catch (const Xapian::DatabaseClosedError &) {
    }
    try {
        // For non-remote databases, keep_alive() is a no-op anyway.
        db.keep_alive();
    } catch (const Xapian::DatabaseClosedError &) {
    }
}

/// Regression test for bug fixed in 1.1.4 - close() should implicitly commit().
DEFINE_TESTCASE(closedb4, writable && !inmemory) {
    Xapian::WritableDatabase wdb(get_writable_database());
    wdb.add_document(Xapian::Document());
    TEST_EQUAL(wdb.get_doccount(), 1);
    wdb.close();
    Xapian::Database db(get_writable_database_as_database());
    TEST_EQUAL(db.get_doccount(), 1);
}

/// Test the effects of close() on transactions
DEFINE_TESTCASE(closedb5, transactions) {
    {
        // If a transaction is active, close() shouldn't implicitly commit().
        Xapian::WritableDatabase wdb = get_writable_database();
        wdb.begin_transaction();
        wdb.add_document(Xapian::Document());
        TEST_EQUAL(wdb.get_doccount(), 1);
        wdb.close();
        Xapian::Database db = get_writable_database_as_database();
        TEST_EQUAL(db.get_doccount(), 0);
    }

    {
        // Same test but for an unflushed transaction.
        Xapian::WritableDatabase wdb = get_writable_database();
        wdb.begin_transaction(false);
        wdb.add_document(Xapian::Document());
        TEST_EQUAL(wdb.get_doccount(), 1);
        wdb.close();
        Xapian::Database db = get_writable_database_as_database();
        TEST_EQUAL(db.get_doccount(), 0);
    }

    {
        // commit_transaction() throws InvalidOperationError when
        // not in a transaction.
        Xapian::WritableDatabase wdb = get_writable_database();
        wdb.close();
        TEST_EXCEPTION(Xapian::InvalidOperationError,
                       wdb.commit_transaction());

        // begin_transaction() is no-op or throws DatabaseClosedError. We may be
        // able to call db.begin_transaction(), but we can't make any changes
        // inside that transaction. If begin_transaction() succeeds, then
        // commit_transaction() either end the transaction or throw
        // DatabaseClosedError.
        try {
            wdb.begin_transaction();
            try {
                wdb.commit_transaction();
            } catch (const Xapian::DatabaseClosedError &) {
            }
        } catch (const Xapian::DatabaseClosedError &) {
        }
    }

    {
        // Same test but for cancel_transaction().
        Xapian::WritableDatabase wdb = get_writable_database();
        wdb.close();
        TEST_EXCEPTION(Xapian::InvalidOperationError,
                       wdb.cancel_transaction());

        try {
            wdb.begin_transaction();
            try {
                wdb.cancel_transaction();
            } catch (const Xapian::DatabaseClosedError &) {
            }
        } catch (const Xapian::DatabaseClosedError &) {
        }
    }
}

/// Database::keep_alive() should fail after close() for a remote database.
DEFINE_TESTCASE(closedb6, remote) {
    Xapian::Database db(get_database("etext"));
    db.close();

    try {
        db.keep_alive();
        FAIL_TEST("Expected DatabaseClosedError wasn't thrown");
    } catch (const Xapian::DatabaseClosedError &) {
    }
}

// Test WritableDatabase methods.
DEFINE_TESTCASE(closedb7, writable) {
    Xapian::WritableDatabase db(get_writable_database());
    db.add_document(Xapian::Document());
    db.close();

    // Since we can't make any changes which need to be committed,
    // db.commit() is a no-op, and so doesn't have to fail.
    try {
        db.commit();
    } catch (const Xapian::DatabaseClosedError &) {
    }

    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.add_document(Xapian::Document()));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.delete_document(1));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.replace_document(1, Xapian::Document()));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.replace_document(2, Xapian::Document()));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.replace_document("Qi", Xapian::Document()));
}

// Test spelling related methods.
DEFINE_TESTCASE(closedb8, writable && spelling) {
    Xapian::WritableDatabase db(get_writable_database());
    db.add_spelling("pneumatic");
    db.add_spelling("pneumonia");
    db.close();

    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.add_spelling("penmanship"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.remove_spelling("pneumatic"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.get_spelling_suggestion("newmonia"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.spellings_begin());
}

// Test synonym related methods.
DEFINE_TESTCASE(closedb9, writable && synonyms) {
    Xapian::WritableDatabase db(get_writable_database());
    db.add_synonym("color", "colour");
    db.add_synonym("honor", "honour");
    db.close();

    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.add_synonym("behavior", "behaviour"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.remove_synonym("honor", "honour"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.clear_synonyms("honor"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.synonyms_begin("color"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.synonym_keys_begin());
}

// Test metadata related methods.
DEFINE_TESTCASE(closedb10, writable && metadata) {
    Xapian::WritableDatabase db(get_writable_database());
    db.set_metadata("foo", "FOO");
    db.set_metadata("bar", "BAR");
    db.close();

    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.set_metadata("test", "TEST"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.get_metadata("foo"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.get_metadata("bar"));
    TEST_EXCEPTION(Xapian::DatabaseClosedError,
                   db.metadata_keys_begin());
}

#define COUNT_NETWORK(CODE) COUNT_EXCEPTION(CODE, NetworkError)

// Iterators used by remotefailure1.
struct remotefailure1_iterators {
    Xapian::Database db;
    Xapian::Document doc1;
    Xapian::PostingIterator pl1;
    Xapian::PostingIterator pl2;
    Xapian::PostingIterator pl1end;
    Xapian::PostingIterator pl2end;
    Xapian::TermIterator tl1;
    Xapian::TermIterator tlend;
    Xapian::TermIterator atl1;
    Xapian::TermIterator atlend;
    Xapian::PositionIterator pil1;
    Xapian::PositionIterator pilend;

    void setup(Xapian::Database db_) {
        db = db_;

        // Set up the iterators for the test.
        pl1 = db.postlist_begin("paragraph");
        pl2 = db.postlist_begin("this");
        ++pl2;
        pl1end = db.postlist_end("paragraph");
        pl2end = db.postlist_end("this");
        tl1 = db.termlist_begin(1);
        tlend = db.termlist_end(1);
        atl1 = db.allterms_begin("t");
        atlend = db.allterms_end("t");
        pil1 = db.positionlist_begin(1, "paragraph");
        pilend = db.positionlist_end(1, "paragraph");
    }

    int perform() {
        int exception_count = 0;

        // Getting a document may throw.
        COUNT_NETWORK(
            doc1 = db.get_document(1);
            // Only do these if get_document() succeeded.
            COUNT_NETWORK(TEST_EQUAL(doc1.get_data().substr(0, 33),
                                     "This is a test document used with"));
            COUNT_NETWORK(doc1.termlist_begin());
        );

        // These should always fail.
        COUNT_NETWORK(db.postlist_begin("paragraph"));
        COUNT_NETWORK(db.get_document(1).get_value(1));
        COUNT_NETWORK(db.termlist_begin(1));
        COUNT_NETWORK(db.positionlist_begin(1, "paragraph"));
        COUNT_NETWORK(db.allterms_begin());
        COUNT_NETWORK(db.allterms_begin("p"));
        COUNT_NETWORK(db.get_termfreq("paragraph"));
        COUNT_NETWORK(db.get_collection_freq("paragraph"));
        COUNT_NETWORK(db.term_exists("paragraph"));
        COUNT_NETWORK(db.get_value_freq(1));
        COUNT_NETWORK(db.get_value_lower_bound(1));
        COUNT_NETWORK(db.get_value_upper_bound(1));
        COUNT_NETWORK(db.valuestream_begin(1));
        COUNT_NETWORK(db.get_doclength(1));
        COUNT_NETWORK(db.get_unique_terms(1));

        // Should always fail.
        COUNT_NETWORK(db.reopen());

        TEST_NOT_EQUAL(pl1, pl1end);
        TEST_NOT_EQUAL(pl2, pl2end);
        TEST_NOT_EQUAL(tl1, tlend);
        TEST_NOT_EQUAL(atl1, atlend);
        TEST_NOT_EQUAL(pil1, pilend);

        COUNT_NETWORK(db.postlist_begin("paragraph"));

        COUNT_NETWORK(TEST_EQUAL(*pl1, 1));
        COUNT_NETWORK(TEST_EQUAL(pl1.get_doclength(), 28));
        COUNT_NETWORK(TEST_EQUAL(pl1.get_unique_terms(), 21));

        COUNT_NETWORK(TEST_EQUAL(*pl2, 2));
        COUNT_NETWORK(TEST_EQUAL(pl2.get_doclength(), 81));
        COUNT_NETWORK(TEST_EQUAL(pl2.get_unique_terms(), 56));

        COUNT_NETWORK(TEST_EQUAL(*tl1, "a"));
        COUNT_NETWORK(TEST_EQUAL(tl1.get_wdf(), 2));
        COUNT_NETWORK(TEST_EQUAL(tl1.get_termfreq(), 3));

        COUNT_NETWORK(TEST_EQUAL(*atl1, "test"));
        COUNT_NETWORK(TEST_EQUAL(atl1.get_termfreq(), 1));

        COUNT_NETWORK(TEST_EQUAL(*pil1, 12));

        // Advancing the iterator may or may not raise an error, but if it
        // doesn't it must return the correct answers.
        COUNT_NETWORK(
            ++pl1;
            COUNT_NETWORK(TEST_EQUAL(*pl1, 2));
            COUNT_NETWORK(TEST_EQUAL(pl1.get_doclength(), 81));
            COUNT_NETWORK(TEST_EQUAL(pl1.get_unique_terms(), 56));
        );

        COUNT_NETWORK(
            ++pl2;
            COUNT_NETWORK(TEST_EQUAL(*pl2, 3));
            COUNT_NETWORK(TEST_EQUAL(pl2.get_doclength(), 15));
            COUNT_NETWORK(TEST_EQUAL(pl2.get_unique_terms(), 14));
        );

        COUNT_NETWORK(
            ++tl1;
            COUNT_NETWORK(TEST_EQUAL(*tl1, "api"));
            COUNT_NETWORK(TEST_EQUAL(tl1.get_wdf(), 1));
            COUNT_NETWORK(TEST_EQUAL(tl1.get_termfreq(), 1));
        );

        COUNT_NETWORK(
            ++atl1;
            COUNT_NETWORK(TEST_EQUAL(*atl1, "that"));
            COUNT_NETWORK(TEST_EQUAL(atl1.get_termfreq(), 2));
        );

        COUNT_NETWORK(
            ++pil1;
            COUNT_NETWORK(TEST_EQUAL(*pil1, 28));
        );

        return exception_count;
    }
};

// Test for a remote server failing.
DEFINE_TESTCASE(remotefailure1, remotetcp) {
#ifdef __WIN32__
    // Calling GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, pid) to kill
    // a whole process group fails under Wine with ERROR_INVALID_HANDLE.
    // We haven't managed to reduce a testcase for this.
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    Xapian::Database db(get_database("apitest_simpledata"));
    remotefailure1_iterators iters;

    // Run the test, checking that we get no exceptions.
    iters.setup(db);
    int exception_count = iters.perform();
    TEST_EQUAL(exception_count, 0);

    // Setup for the next test.
    iters.setup(db);

    // Simulate remote server failure.
    kill_remote(db);

    // Dup stdout to the fds which the database was using, to try to catch
    // issues with lingering references to closed fds.
    vector<int> fds;
    for (int i = 0; i != 6; ++i) {
        fds.push_back(dup(1));
    }

    // Run the test again, checking that we get some "NetworkError" exceptions.
    exception_count = iters.perform();
    TEST_NOT_EQUAL(exception_count, 0);

    // get_description() shouldn't throw an exception.  Actually do something
    // with the description, in case this method is marked as "pure" in the
    // future.
    TEST(!db.get_description().empty());

    for (int fd : fds) {
        close(fd);
    }
}

// There's no remotefailure2 plus other gaps in the numbering - these testcases
// are adapted versions of the closedb testcases, but some closedb testcases
// don't make sense to convert.

/// Check API methods which might either work or throw an exception.
DEFINE_TESTCASE(remotefailure3, remotetcp) {
#ifdef __WIN32__
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    Xapian::Database db(get_database("etext"));
    const string & uuid = db.get_uuid();
    kill_remote(db);
    try {
        TEST_EQUAL(db.get_uuid(), uuid);
    } catch (const Xapian::NetworkError&) {
    }
    try {
        TEST(db.has_positions());
    } catch (const Xapian::NetworkError&) {
    }
    try {
        TEST_EQUAL(db.get_doccount(), 566);
    } catch (const Xapian::NetworkError&) {
    }
    try {
        TEST_EQUAL(db.get_lastdocid(), 566);
    } catch (const Xapian::NetworkError&) {
    }
    try {
        TEST_REL(db.get_doclength_lower_bound(), <, db.get_avlength());
    } catch (const Xapian::NetworkError&) {
    }
    try {
        TEST_REL(db.get_doclength_upper_bound(), >, db.get_avlength());
    } catch (const Xapian::NetworkError&) {
    }
    try {
        TEST(db.get_wdf_upper_bound("king"));
    } catch (const Xapian::NetworkError&) {
    }
    TEST_EXCEPTION(Xapian::NetworkError, db.keep_alive());
}

/// Test the effects of remote server failure on transactions
DEFINE_TESTCASE(remotefailure5, remotetcp) {
#ifdef __WIN32__
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    {
        Xapian::WritableDatabase wdb = get_writable_database();
        kill_remote(wdb);

        // commit_transaction() and cancel_transaction() should throw
        // InvalidOperationError because we aren't in a transaction.
        TEST_EXCEPTION(Xapian::InvalidOperationError,
                       wdb.commit_transaction());

        TEST_EXCEPTION(Xapian::InvalidOperationError,
                       wdb.cancel_transaction());

        // begin_transaction() only sets state locally so works.
        wdb.begin_transaction();
        // commit_transaction() should only communicate with the server if
        // there are changes in the transaction.
        wdb.commit_transaction();

        wdb.begin_transaction();
        // cancel_transaction() should only communicate with the server if
        // there are changes in the transaction.
        wdb.cancel_transaction();
    }

    {
        Xapian::WritableDatabase wdb = get_writable_database();
        wdb.begin_transaction();
        wdb.add_document(Xapian::Document());
        kill_remote(wdb);
        // With a transaction active, commit_transaction() should fail with
        // NetworkError.
        TEST_EXCEPTION(Xapian::NetworkError,
                       wdb.commit_transaction());
    }

    {
        Xapian::WritableDatabase wdb = get_writable_database();
        wdb.begin_transaction();
        wdb.add_document(Xapian::Document());
        kill_remote(wdb);
        // With a transaction active, cancel_transaction() should fail with
        // NetworkError.
        TEST_EXCEPTION(Xapian::NetworkError,
                       wdb.cancel_transaction());
    }
}

// Test WritableDatabase methods.
DEFINE_TESTCASE(remotefailure7, remotetcp) {
#ifdef __WIN32__
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    Xapian::WritableDatabase db(get_writable_database());
    db.add_document(Xapian::Document());
    kill_remote(db);

    // We have a pending change from before the kill so this should fail.
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.commit());
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.add_document(Xapian::Document()));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.delete_document(1));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.replace_document(1, Xapian::Document()));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.replace_document(2, Xapian::Document()));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.replace_document("Qi", Xapian::Document()));
}

// Test spelling related methods.
DEFINE_TESTCASE(remotefailure8, remotetcp) {
#ifdef __WIN32__
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    Xapian::WritableDatabase db(get_writable_database());
    db.add_spelling("pneumatic");
    db.add_spelling("pneumonia");
    kill_remote(db);

    TEST_EXCEPTION(Xapian::NetworkError,
                   db.add_spelling("penmanship"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.remove_spelling("pneumatic"));
    // These methods aren't implemented for remote databases - they're no-ops
    // which don't fail even when we kill the remote server.  Once remote
    // spelling suggestions are working we can uncomment them.
    // TEST_EXCEPTION(Xapian::NetworkError,
    //               db.get_spelling_suggestion("newmonia"));
    // TEST_EXCEPTION(Xapian::NetworkError,
    //               db.spellings_begin());
}

// Test synonym related methods.
DEFINE_TESTCASE(remotefailure9, remotetcp) {
#ifdef __WIN32__
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    Xapian::WritableDatabase db(get_writable_database());
    db.add_synonym("color", "colour");
    db.add_synonym("honor", "honour");
    kill_remote(db);

    TEST_EXCEPTION(Xapian::NetworkError,
                   db.add_synonym("behavior", "behaviour"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.remove_synonym("honor", "honour"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.clear_synonyms("honor"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.synonyms_begin("color"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.synonym_keys_begin());
}

// Test metadata related methods.
DEFINE_TESTCASE(remotefailure10, remotetcp) {
#ifdef __WIN32__
    if (getenv("XAPIAN_TESTSUITE_RUNNING_UNDER_WINE"))
        SKIP_TEST("This testcase doesn't work under Wine");
#endif
    Xapian::WritableDatabase db(get_writable_database());
    db.set_metadata("foo", "FOO");
    db.set_metadata("bar", "BAR");
    kill_remote(db);

    TEST_EXCEPTION(Xapian::NetworkError,
                   db.set_metadata("test", "TEST"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.get_metadata("foo"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.get_metadata("bar"));
    TEST_EXCEPTION(Xapian::NetworkError,
                   db.metadata_keys_begin());
}
