updates.inc

    }
    else {
      variable_set($menus[$loop]['menu_var'], $menus[$loop]['pid']);
    }
    variable_del('phptemplate_' .$menus[$loop]['links_var']);
    variable_del('phptemplate_'. $menus[$loop]['links_var'] .'_more');
    variable_del($menus[$loop]['toggle_var']);
    variable_del($menus[$loop]['more_var']);
    // If user has old xtemplate links in a string, leave them in the var.
    if (isset($ts) && is_array($ts) && is_array($ts[$menus[$loop]['links_var']])) {
      variable_del($menus[$loop]['links_var']);
    }
  }

  if (isset($ts) && is_array($ts)) {
    variable_set('theme_settings', $ts);
  }

  $ret[] = update_sql("UPDATE {system} SET status = 1 WHERE name = 'menu'");

  return $ret;
}

function system_update_152() {
  $ret = array();

  // Postgresql only update
  switch ($GLOBALS['db_type']) {
    case 'pgsql':
      $ret[] = update_sql("ALTER TABLE {forum} DROP shadow");
      break;
    case 'mysql':
    case 'mysqli':
      break;
  }

  return $ret;
}

function system_update_153(){
  $ret = array();
  switch ($GLOBALS['db_type']) {
    case 'pgsql':
      $ret[] = update_sql("ALTER TABLE {contact} DROP CONSTRAINT {contact}_pkey");
      $ret[] = update_sql("CREATE SEQUENCE {contact}_cid_seq");
      db_add_column($ret, 'contact', 'cid', 'int', array('not null' => TRUE, 'default' => "nextval('{contact}_cid_seq')"));
      $ret[] = update_sql("ALTER TABLE {contact} ADD PRIMARY KEY (cid)");
      $ret[] = update_sql("ALTER TABLE {contact} ADD CONSTRAINT {contact}_category_key UNIQUE (category)");
      break;
    case 'mysql':
    case 'mysqli':
      $ret[] = update_sql("ALTER TABLE {contact} DROP PRIMARY KEY");
      $ret[] = update_sql("ALTER TABLE {contact} ADD COLUMN cid int(11) NOT NULL PRIMARY KEY auto_increment");
      $ret[] = update_sql("ALTER TABLE {contact} ADD UNIQUE KEY category (category)");
      break;
  }
  return $ret;
}

function system_update_154() {
  $ret = array();
  switch ($GLOBALS['db_type']) {
    case 'pgsql':
      db_add_column($ret, 'contact', 'weight', 'smallint', array('not null' => TRUE, 'default' => 0));
      db_add_column($ret, 'contact', 'selected', 'smallint', array('not null' => TRUE, 'default' => 0));
      break;
    case 'mysql':
    case 'mysqli':
      $ret[] = update_sql("ALTER TABLE {contact} ADD COLUMN weight tinyint(3) NOT NULL DEFAULT 0");
      $ret[] = update_sql("ALTER TABLE {contact} ADD COLUMN selected tinyint(1) NOT NULL DEFAULT 0");
      break;
  }
  return $ret;
}

function system_update_155() {
  $ret = array();

  // Postgresql only update
  switch ($GLOBALS['db_type']) {
    case 'pgsql':
      $ret[] = update_sql("DROP TABLE {cache}");
      $ret[] = update_sql("CREATE TABLE {cache} (
        cid varchar(255) NOT NULL default '',
        data bytea default '',
        expire integer NOT NULL default '0',
        created integer NOT NULL default '0',
        headers text default '',
        PRIMARY KEY (cid)
        )");
      $ret[] = update_sql("CREATE INDEX {cache}_expire_idx ON {cache}(expire)");
      break;
    case 'mysql':
    case 'mysqli':
      break;
  }

  return $ret;
}

function system_update_156() {
  $ret = array();
  $ret[] = update_sql("DELETE FROM {cache}");
  system_themes();
  return $ret;
}

function system_update_157() {
  $ret = array();
  $ret[] = update_sql("DELETE FROM {url_alias} WHERE src = 'node/feed' AND dst = 'rss.xml'");
  $ret[] = update_sql("INSERT INTO {url_alias} (src, dst) VALUES ('rss.xml', 'node/feed')");
  return $ret;
}

function system_update_158() {
  $ret = array();

  switch ($GLOBALS['db_type']) {
    case 'mysqli':
    case 'mysql':
      $ret[] = update_sql("ALTER TABLE {old_revisions} ADD done tinyint(1) NOT NULL DEFAULT 0");
      $ret[] = update_sql("ALTER TABLE {old_revisions} ADD INDEX (done)");
      break;

    case 'pgsql':
      db_add_column($ret, 'old_revisions', 'done', 'smallint', array('not null' => TRUE, 'default' => 0));
      $ret[] = update_sql('CREATE INDEX {old_revisions}_done_idx ON {old_revisions}(done)');
      break;
  }

  return $ret;
}

/**
 * Retrieve data out of the old_revisions table and put into new revision
 * system.
 *
 * The old_revisions table is not deleted because any data which could not be
 * put into the new system is retained.
 */
function system_update_159() {
  $ret = array();

  $result = db_query_range("SELECT * FROM {old_revisions} WHERE done = 0 AND type IN ('page', 'story', 'poll', 'book', 'forum')", 0, 20);

  $vid = db_next_id('{node_revisions}_vid');
  while ($node = db_fetch_object($result)) {
    $revisions = unserialize($node->revisions);
    if (isset($revisions) && is_array($revisions) && count($revisions) > 0) {
      $revisions_query = array();
      $revisions_args = array();
      $book_query = array();
      $book_args = array();
      $forum_query = array();
      $forum_args = array();
      foreach ($revisions as $version) {
        $revision = array();
        foreach ($version['node'] as $node_field => $node_value) {
          $revision[$node_field] = $node_value;
        }
        $revision['uid'] = $version['uid'];
        $revision['timestamp'] = $version['timestamp'];
        $vid++;
        $revisions_query[] = "(%d, %d, %d, '%s', '%s', '%s', '%s', %d, %d)";
        $revisions_args = array_merge($revisions_args, array($node->nid, $vid, $revision['uid'], $revision['title'], $revision['body'], $revision['teaser'], $revision['log'], $revision['timestamp'], $revision['format']));
        switch ($node->type) {
          case 'forum':
            if ($revision['tid'] > 0) {
              $forum_query[] = "(%d, %d, %d)";
              $forum_args = array_merge($forum_args, array($vid, $node->nid, $revision['tid']));
            }
            break;

          case 'book':
            $book_query[] = "(%d, %d, %d, %d)";
            $book_args = array_merge($book_args, array($vid, $node->nid, $revision['parent'], $revision['weight']));
            break;
        }
      }
      if (count($revisions_query)) {
        $revision_status = db_query("INSERT INTO {node_revisions} (nid, vid, uid, title, body, teaser, log, timestamp, format) VALUES ". implode(',', $revisions_query), $revisions_args);
      }
      if (count($forum_query)) {
        $forum_status = db_query("INSERT INTO {forum} (vid, nid, tid) VALUES ". implode(',', $forum_query), $forum_args);
      }
      if (count($book_query)) {
        $book_status = db_query("INSERT INTO {book} (vid, nid, parent, weight) VALUES ". implode(',', $book_query), $book_args);
      }
      $delete = FALSE;
      switch ($node->type) {
        case 'forum':
          if ($forum_status && $revision_status) {
            $delete = TRUE;
          }
          break;

        case 'book':
          if ($book_status && $revision_status) {
            $delete = TRUE;
          }
          break;

        default:
          if ($revision_status) {
            $delete = TRUE;
          }
          break;
      }

      if ($delete) {
        db_query('DELETE FROM {old_revisions} WHERE nid = %d', $node->nid);
      }
      else {
        db_query('UPDATE {old_revisions} SET done = 1 WHERE nid = %d', $node->nid);
      }
    }
  }

  switch ($GLOBALS['db_type']) {
    case 'mysqli':
    case 'mysql':
      $ret[] = update_sql("UPDATE {sequences} SET id = $vid WHERE name = '{node_revisions}_vid'");
      break;

    case 'pgsql':
      $ret[] = update_sql("SELECT setval('{node_revisions}_vid_seq', $vid)");
      break;
  }

  if (db_num_rows($result) < 20) {
    $ret[] = update_sql('ALTER TABLE {old_revisions} DROP done');
  }
  else {
    $ret['#finished'] = FALSE;
  }

  return $ret;
}

function system_update_160() {
  $types = module_invoke('node', 'get_types');
  if (is_array($types)) {
    foreach($types as $type) {
      if (!is_array(variable_get("node_options_$type", array()))) {
        variable_set("node_options_$type", array());
      }
    }
  }
  return array();
}

function system_update_161() {
  variable_del('forum_icon_path');
  return array();
}

function system_update_162() {
  $ret = array();

  // PostgreSQL only update
  switch ($GLOBALS['db_type']) {
    case 'pgsql':

      $ret[] = update_sql('DROP INDEX {book}_parent');
      $ret[] = update_sql('CREATE INDEX {book}_parent_idx ON {book}(parent)');

      $ret[] = update_sql('DROP INDEX {node_comment_statistics}_timestamp_idx');
      $ret[] = update_sql('CREATE INDEX {node_comment_statistics}_last_comment_timestamp_idx ON {node_comment_statistics}(last_comment_timestamp)');

      $ret[] = update_sql('ALTER TABLE {filters} ALTER delta SET DEFAULT 0');
      $ret[] = update_sql('DROP INDEX {filters}_module_idx');

      $ret[] = update_sql('DROP INDEX {locales_target}_lid_idx');
      $ret[] = update_sql('DROP INDEX {locales_target}_lang_idx');
      $ret[] = update_sql('CREATE INDEX {locales_target}_locale_idx ON {locales_target}(locale)');

      $ret[] = update_sql('DROP INDEX {node}_created');
      $ret[] = update_sql('CREATE INDEX {node}_created_idx ON {node}(created)');
      $ret[] = update_sql('DROP INDEX {node}_changed');
      $ret[] = update_sql('CREATE INDEX {node}_changed_idx ON {node}(changed)');

      $ret[] = update_sql('DROP INDEX {profile_fields}_category');
      $ret[] = update_sql('CREATE INDEX {profile_fields}_category_idx ON {profile_fields}(category)');

      $ret[] = update_sql('DROP INDEX {url_alias}_dst_idx');
      $ret[] = update_sql('CREATE UNIQUE INDEX {url_alias}_dst_idx ON {url_alias}(dst)');

      $ret[] = update_sql('CREATE INDEX {sessions}_uid_idx ON {sessions}(uid)');
      $ret[] = update_sql('CREATE INDEX {sessions}_timestamp_idx ON {sessions}(timestamp)');

      $ret[] = update_sql('ALTER TABLE {accesslog} DROP mask');

      db_change_column($ret, 'accesslog', 'path', 'path', 'text');
      db_change_column($ret, 'accesslog', 'url', 'url', 'text');
      db_change_column($ret, 'watchdog', 'link', 'link', 'text', array('not null' => TRUE, 'default' => "''"));
      db_change_column($ret, 'watchdog', 'location', 'location', 'text', array('not null' => TRUE, 'default' => "''"));
      db_change_column($ret, 'watchdog', 'referer', 'referer', 'text', array('not null' => TRUE, 'default' => "''"));

      break;
  }

  return $ret;
}

function system_update_163() {
  $ret = array();
  if ($GLOBALS['db_type'] == 'mysql' || $GLOBALS['db_type'] == 'mysqli') {
    $ret[] = update_sql('ALTER TABLE {cache} CHANGE data data LONGBLOB');
  }
  return $ret;
}

function system_update_164() {
  $ret = array();

  switch ($GLOBALS['db_type']) {
    case 'mysql':
    case 'mysqli':
      $ret[] = update_sql("CREATE TABLE {poll_votes} (
          nid int(10) unsigned NOT NULL,
          uid int(10) unsigned NOT NULL default 0,
          hostname varchar(128) NOT NULL default '',
          INDEX (nid),
          INDEX (uid),
          INDEX (hostname)
      )");
      break;

    case 'pgsql':
      $ret[] = update_sql("CREATE TABLE {poll_votes} (
          nid int NOT NULL,
          uid int NOT NULL default 0,
          hostname varchar(128) NOT NULL default ''
      )");
      $ret[] = update_sql('CREATE INDEX {poll_votes}_nid_idx ON {poll_votes} (nid)');
      $ret[] = update_sql('CREATE INDEX {poll_votes}_uid_idx ON {poll_votes} (uid)');
      $ret[] = update_sql('CREATE INDEX {poll_votes}_hostname_idx ON {poll_votes} (hostname)');
      break;
  }

  $result = db_query('SELECT nid, polled FROM {poll}');
  while ($poll = db_fetch_object($result)) {
    foreach (explode(' ', $poll->polled) as $polled) {
      if ($polled[0] == '_') {
        // $polled is a user id
        db_query('INSERT INTO {poll_votes} (nid, uid) VALUES (%d, %d)', $poll->nid, substr($polled, 1, -1));
      }
      else {
        // $polled is a host
        db_query("INSERT INTO {poll_votes} (nid, hostname) VALUES (%d, '%s')", $poll->nid, $polled);
      }
    }
  }

  $ret[] = update_sql('ALTER TABLE {poll} DROP polled');

  return $ret;
}

function system_update_165() {
  $cron_last = max(variable_get('drupal_cron_last', 0), variable_get('ping_cron_last', 0));
  variable_set('cron_last', $cron_last);
  variable_del('drupal_cron_last');
  variable_del('ping_cron_last');
  return array();
}

function system_update_166() {
  $ret = array();

  $ret[] = update_sql("DROP TABLE {directory}");
  switch ($GLOBALS['db_type']) {
    case 'mysqli':
    case 'mysql':
      $ret[] = update_sql("CREATE TABLE {client} (
        cid int(10) unsigned NOT NULL auto_increment,
        link varchar(255) NOT NULL default '',
        name varchar(128) NOT NULL default '',
        mail varchar(128) NOT NULL default '',
        slogan longtext NOT NULL,
        mission longtext NOT NULL,
        users int(10) NOT NULL default '0',
        nodes int(10) NOT NULL default '0',
        version varchar(35) NOT NULL default'',
        created int(11) NOT NULL default '0',
        changed int(11) NOT NULL default '0',
        PRIMARY KEY (cid)
      ) TYPE=MyISAM");
      $ret[] = update_sql("CREATE TABLE {client_system} (
        cid int(10) NOT NULL default '0',
        name varchar(255) NOT NULL default '',
        type varchar(255) NOT NULL default '',
        PRIMARY KEY (cid,name)
      ) TYPE=MyISAM");
      break;

    case 'pgsql':
      $ret[] = update_sql("CREATE TABLE {client} (
        cid SERIAL,
        link varchar(255) NOT NULL default '',
        name varchar(128) NOT NULL default '',
        mail varchar(128) NOT NULL default '',
        slogan text NOT NULL default '',
        mission text NOT NULL default '',
        users integer NOT NULL default '0',
        nodes integer NOT NULL default '0',
        version varchar(35) NOT NULL default'',
        created integer NOT NULL default '0',
        changed integer NOT NULL default '0',
        PRIMARY KEY (cid)
      )");
      $ret[] = update_sql("CREATE TABLE {client_system} (
        cid integer NOT NULL,
        name varchar(255) NOT NULL default '',
        type varchar(255) NOT NULL default '',
        PRIMARY KEY (cid,name)
      )");
      break;
  }

  return $ret;
}

function system_update_167() {
  $ret = array();

  switch ($GLOBALS['db_type']) {
    case 'mysqli':
    case 'mysql':
      $ret[] = update_sql("ALTER TABLE {vocabulary_node_types} CHANGE type type varchar(32) NOT NULL default ''");
      break;
    case 'pgsql':
      db_change_column($ret, 'vocabulary_node_types', 'type', 'type', 'varchar(32)', array('not null' => TRUE, 'default' => "''"));
      $ret[] = update_sql("ALTER TABLE {vocabulary_node_types} ADD PRIMARY KEY (vid, type)");
      break;
  }

  return $ret;
}

function system_update_168() {
  $ret = array();

  $ret[] = update_sql("ALTER TABLE {term_hierarchy} ADD PRIMARY KEY (tid, parent)");

  return $ret;
}

function system_update_169() {
  // Warn PGSQL admins if their database is set up incorrectly
  if ($GLOBALS['db_type'] == 'pgsql') {
    $encoding = db_result(db_query('SHOW server_encoding'));
    if (!in_array(strtolower($encoding), array('unicode', 'utf8'))) {
      $msg = 'Your PostgreSQL database is set up with the wrong character encoding ('. $encoding .'). It is possible it will not work as expected. It is advised to recreate it with UTF-8/Unicode encoding. More information can be found in the <a href="http://www.postgresql.org/docs/7.4/interactive/multibyte.html">PostgreSQL documentation</a>.';
      watchdog('php', $msg, WATCHDOG_WARNING);
      drupal_set_message($msg, 'status');
    }
  }

  return _system_update_utf8(array(
    'access', 'accesslog', 'aggregator_category',
    'aggregator_category_feed', 'aggregator_category_item',
    'aggregator_feed', 'aggregator_item', 'authmap', 'blocks',
    'book', 'boxes', 'cache', 'comments', 'contact',
    'node_comment_statistics', 'client', 'client_system', 'files',
    'filter_formats', 'filters', 'flood', 'forum', 'history',
    'locales_meta', 'locales_source', 'locales_target', 'menu',
    'node', 'node_access', 'node_revisions', 'profile_fields',
    'profile_values', 'url_alias', 'permission', 'poll', 'poll_votes',
    'poll_choices', 'role', 'search_dataset', 'search_index',
    'search_total', 'sessions', 'sequences', 'node_counter',
    'system', 'term_data', 'term_hierarchy', 'term_node',
    'term_relation', 'term_synonym', 'users', 'users_roles', 'variable',
    'vocabulary', 'vocabulary_node_types', 'watchdog'
  ));
}

/**
 * Converts tables to UTF-8 encoding.
 *
 * This update is designed to be re-usable by contrib modules and is
 * used by system_update_169().
 */
function _system_update_utf8($tables) {
  // Are we starting this update for the first time?
  if (!isset($_SESSION['update_utf8'])) {
    switch ($GLOBALS['db_type']) {
      // Only for MySQL 4.1+
      case 'mysqli':
        break;
      case 'mysql':
        if (version_compare(mysql_get_server_info($GLOBALS['active_db']), '4.1.0', '<')) {
          return array();
        }
        break;
      case 'pgsql':
        return array();
    }

    // See if database uses UTF-8 already
    global $db_url;
    $url = parse_url(is_array($db_url) ? $db_url['default'] : $db_url);
    $db_name = substr($url['path'], 1);
    $result = db_fetch_array(db_query('SHOW CREATE DATABASE `%s`', $db_name));
    if (preg_match('/utf8/i', array_pop($result))) {
      return array();
    }

    // Make list of tables to convert
    $_SESSION['update_utf8'] = $tables;
    // Keep track of total for progress bar
    $_SESSION['update_utf8_total'] = count($tables);
  }

  // Fetch remaining tables list
  $list = &$_SESSION['update_utf8'];
  $ret = array();

  // Convert a table to UTF-8.
  // We change all text columns to their correspending binary type,
  // then back to text, but with a UTF-8 character set.
  // See: http://dev.mysql.com/doc/refman/4.1/en/charset-conversion.html
  $types = array('char' => 'binary',
                 'varchar' => 'varbinary',
                 'tinytext' => 'tinyblob',
                 'text' => 'blob',
                 'mediumtext' => 'mediumblob',
                 'longtext' => 'longblob');

  // Get next table in list
  $table = array_shift($list);
  $convert_to_binary = array();
  $convert_to_utf8 = array();

  // Set table default charset
  $ret[] = update_sql('ALTER TABLE {'. $table .'} DEFAULT CHARACTER SET utf8');

  // Find out which columns need converting and build SQL statements
  $result = db_query('SHOW FULL COLUMNS FROM {'. $table .'}');
  while ($column = db_fetch_array($result)) {
    list($type) = explode('(', $column['Type']);
    if (isset($types[$type])) {
      $names = 'CHANGE `'. $column['Field'] .'` `'. $column['Field'] .'` ';
      $attributes = ' DEFAULT '. ($column['Default'] == 'NULL' ? 'NULL ' :
                     "'". db_escape_string($column['Default']) ."' ") .
                    ($column['Null'] == 'YES' ? 'NULL' : 'NOT NULL');

      $convert_to_binary[] = $names . preg_replace('/'. $type .'/i', $types[$type], $column['Type']) . $attributes;
      $convert_to_utf8[] = $names . $column['Type'] .' CHARACTER SET utf8'. $attributes;
    }
  }

  if (count($convert_to_binary)) {
    // Convert text columns to binary
    $ret[] = update_sql('ALTER TABLE {'. $table .'} '. implode(', ', $convert_to_binary));
    // Convert binary columns to UTF-8
    $ret[] = update_sql('ALTER TABLE {'. $table .'} '. implode(', ', $convert_to_utf8));
  }

  // Are we done?
  if (count($list) == 0) {
    unset($_SESSION['update_utf8']);
    unset($_SESSION['update_utf8_total']);
    return $ret;
  }

  // Progress percentage
  $ret['#finished'] = 1 - (count($list) / $_SESSION['update_utf8_total']);
  return $ret;
}

function system_update_170() {
  if (!variable_get('update_170_done', false)) {
    switch ($GLOBALS['db_type']) {
      case 'pgsql':
        $ret = array();
        db_change_column($ret, 'system', 'schema_version', 'schema_version', 'smallint', array('not null' => TRUE, 'default' => -1));
        break;

      case 'mysql':
      case 'mysqli':
        db_query('ALTER TABLE {system} CHANGE schema_version schema_version smallint(3) not null default -1');
        break;
    }
    // Set schema version -1 (uninstalled) for disabled modules (only affects contrib).
    db_query('UPDATE {system} SET schema_version = -1 WHERE status = 0 AND schema_version = 0');
  }
  return array();
}

function system_update_171() {
  $ret = array();
  $ret[] = update_sql('DELETE FROM {users_roles} WHERE rid IN ('. DRUPAL_ANONYMOUS_RID. ', '. DRUPAL_AUTHENTICATED_RID. ')');
  return $ret;
}

function system_update_172() {
  // Multi-part update
  if (!isset($_SESSION['system_update_172'])) {
    $_SESSION['system_update_172'] = 0;
    $_SESSION['system_update_172_max'] = db_result(db_query('SELECT MAX(cid) FROM {comments}'));
  }

  include_once './modules/comment.module';

  $limit = 20;
  $result = db_query_range("SELECT cid, thread FROM {comments} WHERE cid > %d", $_SESSION['system_update_172'], 0, $limit);
  while ($comment = db_fetch_object($result)) {
    $_SESSION['system_update_172'] = $comment->cid;
    $thread = explode('.', rtrim($comment->thread, '/'));
    foreach ($thread as $i => $offset) {
      // Decode old-style comment codes: 1,2,...,9,90,91,92,...,99,990,991,...
      $thread[$i] = int2vancode((strlen($offset) - 1) * 10 + substr($offset, -1, 1));
    }
    $thread = implode('.', $thread) .'/';
    db_query("UPDATE {comments} SET thread = '%s' WHERE cid = %d", $thread, $comment->cid);
  }

  if ($_SESSION['system_update_172'] == $_SESSION['system_update_172_max']) {
    unset($_SESSION['system_update_172']);
    unset($_SESSION['system_update_172_max']);
    return array();
  }
  return array('#finished' => $_SESSION['system_update_172'] / $_SESSION['system_update_172_max']);
}

function system_update_173() {
  $ret = array();

  switch ($GLOBALS['db_type']) {
    case 'pgsql':
      // create file_revisions table
      $ret[] = update_sql("CREATE TABLE {file_revisions} (
        fid integer NOT NULL default 0,
        vid integer NOT NULL default 0,
        description varchar(255) NOT NULL default '',
        list smallint NOT NULL default 0,
        PRIMARY KEY (fid, vid))");
      $ret[] = update_sql("INSERT INTO {file_revisions} SELECT fid, vid, description, list FROM {files}");

      // alter files table
      $ret[] = update_sql("CREATE TABLE {files_copy} AS SELECT * FROM {files}");
      $ret[] = update_sql("DROP TABLE {files}");
      $ret[] = update_sql("CREATE TABLE {files} (
        fid SERIAL,
        nid integer NOT NULL default 0,
        filename varchar(255) NOT NULL default '',
        filepath varchar(255) NOT NULL default '',
        filemime varchar(255) NOT NULL default '',
        filesize integer NOT NULL default 0,
        PRIMARY KEY (fid))");
      $ret[] = update_sql("INSERT INTO {files} SELECT DISTINCT ON (fid) fid, nid, filename, filepath, filemime, filesize FROM {files_copy}");
      $ret[] = update_sql("SELECT setval('{files}_fid_seq', max(fid)) FROM {files}");
      $ret[] = update_sql("DROP TABLE {files_copy}");
      break;
    case 'mysqli':
    case 'mysql':
      // create file_revisions table
      $ret[] = update_sql("CREATE TABLE {file_revisions} (
        fid int(10) unsigned NOT NULL default 0,
        vid int(10) unsigned NOT NULL default 0,
        description varchar(255) NOT NULL default '',
        list tinyint(1) unsigned NOT NULL default 0,
        PRIMARY KEY (fid, vid)
        ) TYPE=MyISAM");
      $ret[] = update_sql('INSERT INTO {file_revisions} SELECT fid, vid, description, list FROM {files}');

      // alter files table
      $ret[] = update_sql("CREATE TABLE {files_copy} AS SELECT * FROM {files}");
      $ret[] = update_sql("DROP TABLE {files}");
      $ret[] = update_sql("CREATE TABLE {files} (
        fid int(10) unsigned NOT NULL default 0,
        nid int(10) unsigned NOT NULL default 0,
        filename varchar(255) NOT NULL default '',
        filepath varchar(255) NOT NULL default '',
        filemime varchar(255) NOT NULL default '',
        filesize int(10) unsigned NOT NULL default 0,
        PRIMARY KEY (fid)
        ) TYPE=MyISAM
        /*!40100 DEFAULT CHARACTER SET utf8 */");
      $ret[] = update_sql("INSERT IGNORE INTO {files} SELECT fid, nid, filename, filepath, filemime, filesize FROM {files_copy}");
      $ret[] = update_sql("DROP TABLE {files_copy}");
      break;
  }

  return $ret;
}

function system_update_174() {
  // update comments system variables on upgrade.
  $mode = variable_get('comment_default_mode', 4);
  if ($mode > 0) {
    variable_set('comment_default_mode', $mode - 1);
  }
  $order = variable_get('comment_default_order', 1);
  if ($order > 0) {
    variable_set('comment_default_order', $order - 1);
  }
  return array();
}