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---

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mysql/src/5.1-dbg/sql/sql_parse.cc

Go to the documentation of this file.

/* Copyright (C) 2000-2003 MySQL AB

   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, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#define MYSQL_LEX 1
#include "mysql_priv.h"
#include "sql_repl.h"
#include "rpl_filter.h"
#include "repl_failsafe.h"
#include <m_ctype.h>
#include <myisam.h>
#include <my_dir.h>

#include "sp_head.h"
#include "sp.h"
#include "sp_cache.h"
#include "events.h"
#include "event_timed.h"

#ifdef HAVE_OPENSSL
/*
  Without SSL the handshake consists of one packet. This packet
  has both client capabilites and scrambled password.
  With SSL the handshake might consist of two packets. If the first
  packet (client capabilities) has CLIENT_SSL flag set, we have to
  switch to SSL and read the second packet. The scrambled password
  is in the second packet and client_capabilites field will be ignored.
  Maybe it is better to accept flags other than CLIENT_SSL from the
  second packet?
*/
#define SSL_HANDSHAKE_SIZE      2
#define NORMAL_HANDSHAKE_SIZE   6
#define MIN_HANDSHAKE_SIZE      2
#else
#define MIN_HANDSHAKE_SIZE      6
#endif /* HAVE_OPENSSL */

/* Used in error handling only */
#define SP_TYPE_STRING(LP) \
  ((LP)->sphead->m_type == TYPE_ENUM_FUNCTION ? "FUNCTION" : "PROCEDURE")
#define SP_COM_STRING(LP) \
  ((LP)->sql_command == SQLCOM_CREATE_SPFUNCTION || \
   (LP)->sql_command == SQLCOM_ALTER_FUNCTION || \
   (LP)->sql_command == SQLCOM_SHOW_CREATE_FUNC || \
   (LP)->sql_command == SQLCOM_DROP_FUNCTION ? \
   "FUNCTION" : "PROCEDURE")

#ifdef SOLARIS
extern "C" int gethostname(char *name, int namelen);
#endif

static void time_out_user_resource_limits(THD *thd, USER_CONN *uc);
#ifndef NO_EMBEDDED_ACCESS_CHECKS
static int check_for_max_user_connections(THD *thd, USER_CONN *uc);
static void decrease_user_connections(USER_CONN *uc);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
static bool check_multi_update_lock(THD *thd);
static void remove_escape(char *name);
static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables);

const char *any_db="*any*";     // Special symbol for check_access

const LEX_STRING command_name[]={
  C_STRING_WITH_LEN("Sleep"),
  C_STRING_WITH_LEN("Quit"),
  C_STRING_WITH_LEN("Init DB"),
  C_STRING_WITH_LEN("Query"),
  C_STRING_WITH_LEN("Field List"),
  C_STRING_WITH_LEN("Create DB"),
  C_STRING_WITH_LEN("Drop DB"),
  C_STRING_WITH_LEN("Refresh"),
  C_STRING_WITH_LEN("Shutdown"),
  C_STRING_WITH_LEN("Statistics"),
  C_STRING_WITH_LEN("Processlist"),
  C_STRING_WITH_LEN("Connect"),
  C_STRING_WITH_LEN("Kill"),
  C_STRING_WITH_LEN("Debug"),
  C_STRING_WITH_LEN("Ping"),
  C_STRING_WITH_LEN("Time"),
  C_STRING_WITH_LEN("Delayed insert"),
  C_STRING_WITH_LEN("Change user"),
  C_STRING_WITH_LEN("Binlog Dump"),
  C_STRING_WITH_LEN("Table Dump"),
  C_STRING_WITH_LEN("Connect Out"),
  C_STRING_WITH_LEN("Register Slave"),
  C_STRING_WITH_LEN("Prepare"),
  C_STRING_WITH_LEN("Execute"),
  C_STRING_WITH_LEN("Long Data"),
  C_STRING_WITH_LEN("Close stmt"),
  C_STRING_WITH_LEN("Reset stmt"),
  C_STRING_WITH_LEN("Set option"),
  C_STRING_WITH_LEN("Fetch"),
  C_STRING_WITH_LEN("Daemon"),
  C_STRING_WITH_LEN("Error")  // Last command number
};

const char *xa_state_names[]={
  "NON-EXISTING", "ACTIVE", "IDLE", "PREPARED"
};

#ifdef __WIN__
static void  test_signal(int sig_ptr)
{
#if !defined( DBUG_OFF)
  MessageBox(NULL,"Test signal","DBUG",MB_OK);
#endif
}
static void init_signals(void)
{
  int signals[7] = {SIGINT,SIGILL,SIGFPE,SIGSEGV,SIGTERM,SIGBREAK,SIGABRT } ;
  for (int i=0 ; i < 7 ; i++)
    signal( signals[i], test_signal) ;
}
#endif

static void unlock_locked_tables(THD *thd)
{
  if (thd->locked_tables)
  {
    thd->lock=thd->locked_tables;
    thd->locked_tables=0;                       // Will be automatically closed
    close_thread_tables(thd);                   // Free tables
  }
}


bool end_active_trans(THD *thd)
{
  int error=0;
  DBUG_ENTER("end_active_trans");
  if (unlikely(thd->in_sub_stmt))
  {
    my_error(ER_COMMIT_NOT_ALLOWED_IN_SF_OR_TRG, MYF(0));
    DBUG_RETURN(1);
  }
  if (thd->transaction.xid_state.xa_state != XA_NOTR)
  {
    my_error(ER_XAER_RMFAIL, MYF(0),
             xa_state_names[thd->transaction.xid_state.xa_state]);
    DBUG_RETURN(1);
  }
  if (thd->options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN |
                      OPTION_TABLE_LOCK))
  {
    DBUG_PRINT("info",("options: 0x%lx", (ulong) thd->options));
    /* Safety if one did "drop table" on locked tables */
    if (!thd->locked_tables)
      thd->options&= ~OPTION_TABLE_LOCK;
    thd->server_status&= ~SERVER_STATUS_IN_TRANS;
    if (ha_commit(thd))
      error=1;
  }
  thd->options&= ~(OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE |
                   OPTION_KEEP_LOG);
  DBUG_RETURN(error);
}

bool begin_trans(THD *thd)
{
  int error=0;
  if (unlikely(thd->in_sub_stmt))
  {
    my_error(ER_COMMIT_NOT_ALLOWED_IN_SF_OR_TRG, MYF(0));
    return 1;
  }
  if (thd->locked_tables)
  {
    thd->lock=thd->locked_tables;
    thd->locked_tables=0;                       // Will be automatically closed
    close_thread_tables(thd);                   // Free tables
  }
  if (end_active_trans(thd))
    error= -1;
  else
  {
    LEX *lex= thd->lex;
    thd->options|= OPTION_BEGIN;
    thd->server_status|= SERVER_STATUS_IN_TRANS;
    if (lex->start_transaction_opt & MYSQL_START_TRANS_OPT_WITH_CONS_SNAPSHOT)
      error= ha_start_consistent_snapshot(thd);
  }
  return error;
}

#ifdef HAVE_REPLICATION
/*
  Returns true if all tables should be ignored
*/
inline bool all_tables_not_ok(THD *thd, TABLE_LIST *tables)
{
  return rpl_filter->is_on() && tables && !thd->spcont &&
         !rpl_filter->tables_ok(thd->db, tables);
}
#endif


static bool some_non_temp_table_to_be_updated(THD *thd, TABLE_LIST *tables)
{
  for (TABLE_LIST *table= tables; table; table= table->next_global)
  {
    DBUG_ASSERT(table->db && table->table_name);
    if (table->updating &&
        !find_temporary_table(thd, table->db, table->table_name))
      return 1;
  }
  return 0;
}

#ifndef NO_EMBEDDED_ACCESS_CHECKS
static HASH hash_user_connections;

static int get_or_create_user_conn(THD *thd, const char *user,
                                   const char *host,
                                   USER_RESOURCES *mqh)
{
  int return_val= 0;
  uint temp_len, user_len;
  char temp_user[USER_HOST_BUFF_SIZE];
  struct  user_conn *uc;

  DBUG_ASSERT(user != 0);
  DBUG_ASSERT(host != 0);

  user_len= strlen(user);
  temp_len= (strmov(strmov(temp_user, user)+1, host) - temp_user)+1;
  (void) pthread_mutex_lock(&LOCK_user_conn);
  if (!(uc = (struct  user_conn *) hash_search(&hash_user_connections,
                                               (byte*) temp_user, temp_len)))
  {
    /* First connection for user; Create a user connection object */
    if (!(uc= ((struct user_conn*)
               my_malloc(sizeof(struct user_conn) + temp_len+1,
                         MYF(MY_WME)))))
    {
      net_send_error(thd, 0, NullS);            // Out of memory
      return_val= 1;
      goto end;
    }
    uc->user=(char*) (uc+1);
    memcpy(uc->user,temp_user,temp_len+1);
    uc->host= uc->user + user_len +  1;
    uc->len= temp_len;
    uc->connections= uc->questions= uc->updates= uc->conn_per_hour= 0;
    uc->user_resources= *mqh;
    uc->intime= thd->thr_create_time;
    if (my_hash_insert(&hash_user_connections, (byte*) uc))
    {
      my_free((char*) uc,0);
      net_send_error(thd, 0, NullS);            // Out of memory
      return_val= 1;
      goto end;
    }
  }
  thd->user_connect=uc;
  uc->connections++;
end:
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  return return_val;

}
#endif /* !NO_EMBEDDED_ACCESS_CHECKS */


/*
  Check if user exist and password supplied is correct. 

  SYNOPSIS
    check_user()
    thd          thread handle, thd->security_ctx->{host,user,ip} are used
    command      originator of the check: now check_user is called
                 during connect and change user procedures; used for 
                 logging.
    passwd       scrambled password received from client
    passwd_len   length of scrambled password
    db           database name to connect to, may be NULL
    check_count  dont know exactly

    Note, that host, user and passwd may point to communication buffer.
    Current implementation does not depend on that, but future changes
    should be done with this in mind; 'thd' is INOUT, all other params
    are 'IN'.

  RETURN VALUE
    0  OK; thd->security_ctx->user/master_access/priv_user/db_access and
       thd->db are updated; OK is sent to client;
   -1  access denied or handshake error; error is sent to client;
   >0  error, not sent to client
*/

int check_user(THD *thd, enum enum_server_command command, 
               const char *passwd, uint passwd_len, const char *db,
               bool check_count)
{
  DBUG_ENTER("check_user");
  
#ifdef NO_EMBEDDED_ACCESS_CHECKS
  thd->main_security_ctx.master_access= GLOBAL_ACLS;       // Full rights
  /* Change database if necessary */
  if (db && db[0])
  {
    /*
      thd->db is saved in caller and needs to be freed by caller if this
      function returns 0
    */
    thd->reset_db(NULL, 0);
    if (mysql_change_db(thd, db, FALSE))
    {
      /* Send the error to the client */
      net_send_error(thd);
      DBUG_RETURN(-1);
    }
  }
  send_ok(thd);
  DBUG_RETURN(0);
#else

  my_bool opt_secure_auth_local;
  pthread_mutex_lock(&LOCK_global_system_variables);
  opt_secure_auth_local= opt_secure_auth;
  pthread_mutex_unlock(&LOCK_global_system_variables);
  
  /*
    If the server is running in secure auth mode, short scrambles are 
    forbidden.
  */
  if (opt_secure_auth_local && passwd_len == SCRAMBLE_LENGTH_323)
  {
    net_printf_error(thd, ER_NOT_SUPPORTED_AUTH_MODE);
    general_log_print(thd, COM_CONNECT, ER(ER_NOT_SUPPORTED_AUTH_MODE));
    DBUG_RETURN(-1);
  }
  if (passwd_len != 0 &&
      passwd_len != SCRAMBLE_LENGTH &&
      passwd_len != SCRAMBLE_LENGTH_323)
    DBUG_RETURN(ER_HANDSHAKE_ERROR);

  /*
    Clear thd->db as it points to something, that will be freed when 
    connection is closed. We don't want to accidentally free a wrong pointer
    if connect failed. Also in case of 'CHANGE USER' failure, current
    database will be switched to 'no database selected'.
  */
  thd->reset_db(NULL, 0);

  USER_RESOURCES ur;
  int res= acl_getroot(thd, &ur, passwd, passwd_len);
#ifndef EMBEDDED_LIBRARY
  if (res == -1)
  {
    /*
      This happens when client (new) sends password scrambled with
      scramble(), but database holds old value (scrambled with
      scramble_323()). Here we please client to send scrambled_password
      in old format.
    */
    NET *net= &thd->net;
    if (opt_secure_auth_local)
    {
      net_printf_error(thd, ER_SERVER_IS_IN_SECURE_AUTH_MODE,
                       thd->main_security_ctx.user,
                       thd->main_security_ctx.host_or_ip);
      general_log_print(thd, COM_CONNECT, ER(ER_SERVER_IS_IN_SECURE_AUTH_MODE),
                        thd->main_security_ctx.user,
                        thd->main_security_ctx.host_or_ip);
      DBUG_RETURN(-1);
    }
    /* We have to read very specific packet size */
    if (send_old_password_request(thd) ||
        my_net_read(net) != SCRAMBLE_LENGTH_323 + 1)
    {
      inc_host_errors(&thd->remote.sin_addr);
      DBUG_RETURN(ER_HANDSHAKE_ERROR);
    }
    /* Final attempt to check the user based on reply */
    /* So as passwd is short, errcode is always >= 0 */
    res= acl_getroot(thd, &ur, (char *) net->read_pos, SCRAMBLE_LENGTH_323);
  }
#endif /*EMBEDDED_LIBRARY*/
  /* here res is always >= 0 */
  if (res == 0)
  {
    if (!(thd->main_security_ctx.master_access &
          NO_ACCESS)) // authentication is OK
    {
      DBUG_PRINT("info",
                 ("Capabilities: %lx  packet_length: %ld  Host: '%s'  "
                  "Login user: '%s' Priv_user: '%s'  Using password: %s "
                  "Access: %u  db: '%s'",
                  thd->client_capabilities,
                  thd->max_client_packet_length,
                  thd->main_security_ctx.host_or_ip,
                  thd->main_security_ctx.user,
                  thd->main_security_ctx.priv_user,
                  passwd_len ? "yes": "no",
                  thd->main_security_ctx.master_access,
                  (thd->db ? thd->db : "*none*")));

      if (check_count)
      {
        VOID(pthread_mutex_lock(&LOCK_thread_count));
        bool count_ok= thread_count <= max_connections + delayed_insert_threads
                       || (thd->main_security_ctx.master_access & SUPER_ACL);
        VOID(pthread_mutex_unlock(&LOCK_thread_count));
        if (!count_ok)
        {                                         // too many connections
          net_send_error(thd, ER_CON_COUNT_ERROR);
          DBUG_RETURN(-1);
        }
      }

      /* Why logging is performed before all checks've passed? */
      general_log_print(thd, command,
                        (thd->main_security_ctx.priv_user ==
                         thd->main_security_ctx.user ?
                         (char*) "%s@%s on %s" :
                         (char*) "%s@%s as anonymous on %s"),
                        thd->main_security_ctx.user,
                        thd->main_security_ctx.host_or_ip,
                        db ? db : (char*) "");

      /*
        This is the default access rights for the current database.  It's
        set to 0 here because we don't have an active database yet (and we
        may not have an active database to set.
      */
      thd->main_security_ctx.db_access=0;

      /* Don't allow user to connect if he has done too many queries */
      if ((ur.questions || ur.updates || ur.conn_per_hour || ur.user_conn ||
           max_user_connections) &&
          get_or_create_user_conn(thd,
            (opt_old_style_user_limits ? thd->main_security_ctx.user :
             thd->main_security_ctx.priv_user),
            (opt_old_style_user_limits ? thd->main_security_ctx.host_or_ip :
             thd->main_security_ctx.priv_host),
            &ur))
        DBUG_RETURN(-1);
      if (thd->user_connect &&
          (thd->user_connect->user_resources.conn_per_hour ||
           thd->user_connect->user_resources.user_conn ||
           max_user_connections) &&
          check_for_max_user_connections(thd, thd->user_connect))
        DBUG_RETURN(-1);

      /* Change database if necessary */
      if (db && db[0])
      {
        if (mysql_change_db(thd, db, FALSE))
        {
          /* Send error to the client */
          net_send_error(thd);
          if (thd->user_connect)
            decrease_user_connections(thd->user_connect);
          DBUG_RETURN(-1);
        }
      }
      send_ok(thd);
      thd->password= test(passwd_len);          // remember for error messages 
      /* Ready to handle queries */
      DBUG_RETURN(0);
    }
  }
  else if (res == 2) // client gave short hash, server has long hash
  {
    net_printf_error(thd, ER_NOT_SUPPORTED_AUTH_MODE);
    general_log_print(thd, COM_CONNECT, ER(ER_NOT_SUPPORTED_AUTH_MODE));
    DBUG_RETURN(-1);
  }
  net_printf_error(thd, ER_ACCESS_DENIED_ERROR,
                   thd->main_security_ctx.user,
                   thd->main_security_ctx.host_or_ip,
                   passwd_len ? ER(ER_YES) : ER(ER_NO));
  general_log_print(thd, COM_CONNECT, ER(ER_ACCESS_DENIED_ERROR),
                    thd->main_security_ctx.user,
                    thd->main_security_ctx.host_or_ip,
                    passwd_len ? ER(ER_YES) : ER(ER_NO));
  DBUG_RETURN(-1);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
}

/*
  Check for maximum allowable user connections, if the mysqld server is
  started with corresponding variable that is greater then 0.
*/

extern "C" byte *get_key_conn(user_conn *buff, uint *length,
                              my_bool not_used __attribute__((unused)))
{
  *length=buff->len;
  return (byte*) buff->user;
}

extern "C" void free_user(struct user_conn *uc)
{
  my_free((char*) uc,MYF(0));
}

void init_max_user_conn(void)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  (void) hash_init(&hash_user_connections,system_charset_info,max_connections,
                   0,0,
                   (hash_get_key) get_key_conn, (hash_free_key) free_user,
                   0);
#endif
}


/*
  check if user has already too many connections
  
  SYNOPSIS
  check_for_max_user_connections()
  thd                   Thread handle
  uc                    User connect object

  NOTES
    If check fails, we decrease user connection count, which means one
    shouldn't call decrease_user_connections() after this function.

  RETURN
    0   ok
    1   error
*/

#ifndef NO_EMBEDDED_ACCESS_CHECKS

static int check_for_max_user_connections(THD *thd, USER_CONN *uc)
{
  int error=0;
  DBUG_ENTER("check_for_max_user_connections");

  (void) pthread_mutex_lock(&LOCK_user_conn);
  if (max_user_connections && !uc->user_resources.user_conn &&
      max_user_connections < (uint) uc->connections)
  {
    net_printf_error(thd, ER_TOO_MANY_USER_CONNECTIONS, uc->user);
    error=1;
    goto end;
  }
  time_out_user_resource_limits(thd, uc);
  if (uc->user_resources.user_conn &&
      uc->user_resources.user_conn < uc->connections)
  {
    net_printf_error(thd, ER_USER_LIMIT_REACHED, uc->user,
                     "max_user_connections",
                     (long) uc->user_resources.user_conn);
    error= 1;
    goto end;
  }
  if (uc->user_resources.conn_per_hour &&
      uc->user_resources.conn_per_hour <= uc->conn_per_hour)
  {
    net_printf_error(thd, ER_USER_LIMIT_REACHED, uc->user,
                     "max_connections_per_hour",
                     (long) uc->user_resources.conn_per_hour);
    error=1;
    goto end;
  }
  uc->conn_per_hour++;

  end:
  if (error)
    uc->connections--; // no need for decrease_user_connections() here
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  DBUG_RETURN(error);
}

/*
  Decrease user connection count

  SYNOPSIS
    decrease_user_connections()
    uc                  User connection object

  NOTES
    If there is a n user connection object for a connection
    (which only happens if 'max_user_connections' is defined or
    if someone has created a resource grant for a user), then
    the connection count is always incremented on connect.

    The user connect object is not freed if some users has
    'max connections per hour' defined as we need to be able to hold
    count over the lifetime of the connection.
*/

static void decrease_user_connections(USER_CONN *uc)
{
  DBUG_ENTER("decrease_user_connections");
  (void) pthread_mutex_lock(&LOCK_user_conn);
  DBUG_ASSERT(uc->connections);
  if (!--uc->connections && !mqh_used)
  {
    /* Last connection for user; Delete it */
    (void) hash_delete(&hash_user_connections,(byte*) uc);
  }
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  DBUG_VOID_RETURN;
}

#endif /* NO_EMBEDDED_ACCESS_CHECKS */


void free_max_user_conn(void)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  hash_free(&hash_user_connections);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
}



/*
  Mark all commands that somehow changes a table
  This is used to check number of updates / hour

  sql_command is actually set to SQLCOM_END sometimes
  so we need the +1 to include it in the array.

  See COMMAND_FLAG_xxx for different type of commands
     2  - query that returns meaningful ROW_COUNT() -
          a number of modified rows
*/

uint sql_command_flags[SQLCOM_END+1];

void init_update_queries(void)
{
  bzero((gptr) &sql_command_flags, sizeof(sql_command_flags));

  sql_command_flags[SQLCOM_CREATE_TABLE]=   CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_CREATE_INDEX]=   CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_ALTER_TABLE]=    CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_TRUNCATE]=       CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_DROP_TABLE]=     CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_LOAD]=           CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_CREATE_DB]=      CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_DROP_DB]=        CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_RENAME_TABLE]=   CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_BACKUP_TABLE]=   CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_RESTORE_TABLE]=  CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_DROP_INDEX]=     CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_CREATE_VIEW]=    CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_DROP_VIEW]=      CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_CREATE_EVENT]=   CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_ALTER_EVENT]=    CF_CHANGES_DATA;
  sql_command_flags[SQLCOM_DROP_EVENT]=     CF_CHANGES_DATA;  

  sql_command_flags[SQLCOM_UPDATE]=         CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_UPDATE_MULTI]=   CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_INSERT]=         CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_INSERT_SELECT]=  CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_DELETE]=         CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_DELETE_MULTI]=   CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_REPLACE]=        CF_CHANGES_DATA | CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_REPLACE_SELECT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT;

  sql_command_flags[SQLCOM_SHOW_STATUS_PROC]= CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_STATUS_FUNC]= CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_STATUS]=      CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_DATABASES]=   CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_TRIGGERS]=    CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_EVENTS]=      CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_OPEN_TABLES]= CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_PLUGINS]=     CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_FIELDS]=      CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_KEYS]=        CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_VARIABLES]=   CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_CHARSETS]=    CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_COLLATIONS]=  CF_STATUS_COMMAND;
  sql_command_flags[SQLCOM_SHOW_STATUS_PROC]= CF_STATUS_COMMAND;

  sql_command_flags[SQLCOM_SHOW_TABLES]=       (CF_STATUS_COMMAND |
                                                CF_SHOW_TABLE_COMMAND);
  sql_command_flags[SQLCOM_SHOW_TABLE_STATUS]= (CF_STATUS_COMMAND |
                                                CF_SHOW_TABLE_COMMAND);

  /*
    The following is used to preserver CF_ROW_COUNT during the
    a CALL or EXECUTE statement, so the value generated by the
    last called (or executed) statement is preserved.
    See mysql_execute_command() for how CF_ROW_COUNT is used.
  */
  sql_command_flags[SQLCOM_CALL]=               CF_HAS_ROW_COUNT;
  sql_command_flags[SQLCOM_EXECUTE]=            CF_HAS_ROW_COUNT;
}


bool is_update_query(enum enum_sql_command command)
{
  DBUG_ASSERT(command >= 0 && command <= SQLCOM_END);
  return (sql_command_flags[command] & CF_CHANGES_DATA) != 0;
}

/*
  Reset per-hour user resource limits when it has been more than
  an hour since they were last checked

  SYNOPSIS:
    time_out_user_resource_limits()
    thd                 Thread handler
    uc                  User connection details

  NOTE:
    This assumes that the LOCK_user_conn mutex has been acquired, so it is
    safe to test and modify members of the USER_CONN structure.
*/

static void time_out_user_resource_limits(THD *thd, USER_CONN *uc)
{
  time_t check_time = thd->start_time ?  thd->start_time : time(NULL);
  DBUG_ENTER("time_out_user_resource_limits");

  /* If more than a hour since last check, reset resource checking */
  if (check_time  - uc->intime >= 3600)
  {
    uc->questions=1;
    uc->updates=0;
    uc->conn_per_hour=0;
    uc->intime=check_time;
  }

  DBUG_VOID_RETURN;
}


/*
  Check if maximum queries per hour limit has been reached
  returns 0 if OK.
*/

static bool check_mqh(THD *thd, uint check_command)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  bool error= 0;
  USER_CONN *uc=thd->user_connect;
  DBUG_ENTER("check_mqh");
  DBUG_ASSERT(uc != 0);

  (void) pthread_mutex_lock(&LOCK_user_conn);

  time_out_user_resource_limits(thd, uc);

  /* Check that we have not done too many questions / hour */
  if (uc->user_resources.questions &&
      uc->questions++ >= uc->user_resources.questions)
  {
    net_printf_error(thd, ER_USER_LIMIT_REACHED, uc->user, "max_questions",
                     (long) uc->user_resources.questions);
    error=1;
    goto end;
  }
  if (check_command < (uint) SQLCOM_END)
  {
    /* Check that we have not done too many updates / hour */
    if (uc->user_resources.updates &&
        (sql_command_flags[check_command] & CF_CHANGES_DATA) &&
        uc->updates++ >= uc->user_resources.updates)
    {
      net_printf_error(thd, ER_USER_LIMIT_REACHED, uc->user, "max_updates",
                       (long) uc->user_resources.updates);
      error=1;
      goto end;
    }
  }
end:
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  DBUG_RETURN(error);
#else
  return (0);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
}


static void reset_mqh(LEX_USER *lu, bool get_them= 0)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  (void) pthread_mutex_lock(&LOCK_user_conn);
  if (lu)  // for GRANT
  {
    USER_CONN *uc;
    uint temp_len=lu->user.length+lu->host.length+2;
    char temp_user[USER_HOST_BUFF_SIZE];

    memcpy(temp_user,lu->user.str,lu->user.length);
    memcpy(temp_user+lu->user.length+1,lu->host.str,lu->host.length);
    temp_user[lu->user.length]='\0'; temp_user[temp_len-1]=0;
    if ((uc = (struct  user_conn *) hash_search(&hash_user_connections,
                                                (byte*) temp_user, temp_len)))
    {
      uc->questions=0;
      get_mqh(temp_user,&temp_user[lu->user.length+1],uc);
      uc->updates=0;
      uc->conn_per_hour=0;
    }
  }
  else
  {
    /* for FLUSH PRIVILEGES and FLUSH USER_RESOURCES */
    for (uint idx=0;idx < hash_user_connections.records; idx++)
    {
      USER_CONN *uc=(struct user_conn *) hash_element(&hash_user_connections,
                                                      idx);
      if (get_them)
        get_mqh(uc->user,uc->host,uc);
      uc->questions=0;
      uc->updates=0;
      uc->conn_per_hour=0;
    }
  }
  (void) pthread_mutex_unlock(&LOCK_user_conn);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
}

void thd_init_client_charset(THD *thd, uint cs_number)
{
  /*
   Use server character set and collation if
   - opt_character_set_client_handshake is not set
   - client has not specified a character set
   - client character set is the same as the servers
   - client character set doesn't exists in server
  */
  if (!opt_character_set_client_handshake ||
      !(thd->variables.character_set_client= get_charset(cs_number, MYF(0))) ||
      !my_strcasecmp(&my_charset_latin1,
                     global_system_variables.character_set_client->name,
                     thd->variables.character_set_client->name))
  {
    thd->variables.character_set_client=
      global_system_variables.character_set_client;
    thd->variables.collation_connection=
      global_system_variables.collation_connection;
    thd->variables.character_set_results=
      global_system_variables.character_set_results;
  }
  else
  {
    thd->variables.character_set_results=
      thd->variables.collation_connection= 
      thd->variables.character_set_client;
  }
}


/*
    Perform handshake, authorize client and update thd ACL variables.
  SYNOPSIS
    check_connection()
    thd  thread handle

  RETURN
     0  success, OK is sent to user, thd is updated.
    -1  error, which is sent to user
   > 0  error code (not sent to user)
*/

#ifndef EMBEDDED_LIBRARY
static int check_connection(THD *thd)
{
  uint connect_errors= 0;
  NET *net= &thd->net;
  ulong pkt_len= 0;
  char *end;

  DBUG_PRINT("info",
             ("New connection received on %s", vio_description(net->vio)));
#ifdef SIGNAL_WITH_VIO_CLOSE
  thd->set_active_vio(net->vio);
#endif

  if (!thd->main_security_ctx.host)         // If TCP/IP connection
  {
    char ip[30];

    if (vio_peer_addr(net->vio, ip, &thd->peer_port))
      return (ER_BAD_HOST_ERROR);
    if (!(thd->main_security_ctx.ip= my_strdup(ip,MYF(0))))
      return (ER_OUT_OF_RESOURCES);
    thd->main_security_ctx.host_or_ip= thd->main_security_ctx.ip;
    vio_in_addr(net->vio,&thd->remote.sin_addr);
    if (!(specialflag & SPECIAL_NO_RESOLVE))
    {
      vio_in_addr(net->vio,&thd->remote.sin_addr);
      thd->main_security_ctx.host=
        ip_to_hostname(&thd->remote.sin_addr, &connect_errors);
      /* Cut very long hostnames to avoid possible overflows */
      if (thd->main_security_ctx.host)
      {
        if (thd->main_security_ctx.host != my_localhost)
          thd->main_security_ctx.host[min(strlen(thd->main_security_ctx.host),
                                          HOSTNAME_LENGTH)]= 0;
        thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;
      }
      if (connect_errors > max_connect_errors)
        return(ER_HOST_IS_BLOCKED);
    }
    DBUG_PRINT("info",("Host: %s  ip: %s",
                       (thd->main_security_ctx.host ?
                        thd->main_security_ctx.host : "unknown host"),
                       (thd->main_security_ctx.ip ?
                        thd->main_security_ctx.ip : "unknown ip")));
    if (acl_check_host(thd->main_security_ctx.host, thd->main_security_ctx.ip))
      return(ER_HOST_NOT_PRIVILEGED);
  }
  else /* Hostname given means that the connection was on a socket */
  {
    DBUG_PRINT("info",("Host: %s", thd->main_security_ctx.host));
    thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;
    thd->main_security_ctx.ip= 0;
    /* Reset sin_addr */
    bzero((char*) &thd->remote, sizeof(thd->remote));
  }
  vio_keepalive(net->vio, TRUE);
  {
    /* buff[] needs to big enough to hold the server_version variable */
    char buff[SERVER_VERSION_LENGTH + SCRAMBLE_LENGTH + 64];
    ulong client_flags = (CLIENT_LONG_FLAG | CLIENT_CONNECT_WITH_DB |
                          CLIENT_PROTOCOL_41 | CLIENT_SECURE_CONNECTION);

    if (opt_using_transactions)
      client_flags|=CLIENT_TRANSACTIONS;
#ifdef HAVE_COMPRESS
    client_flags |= CLIENT_COMPRESS;
#endif /* HAVE_COMPRESS */
#ifdef HAVE_OPENSSL
    if (ssl_acceptor_fd)
      client_flags |= CLIENT_SSL;       /* Wow, SSL is available! */
#endif /* HAVE_OPENSSL */

    end= strnmov(buff, server_version, SERVER_VERSION_LENGTH) + 1;
    int4store((uchar*) end, thd->thread_id);
    end+= 4;
    /*
      So as check_connection is the only entry point to authorization
      procedure, scramble is set here. This gives us new scramble for
      each handshake.
    */
    create_random_string(thd->scramble, SCRAMBLE_LENGTH, &thd->rand);
    /*
      Old clients does not understand long scrambles, but can ignore packet
      tail: that's why first part of the scramble is placed here, and second
      part at the end of packet.
    */
    end= strmake(end, thd->scramble, SCRAMBLE_LENGTH_323) + 1;
   
    int2store(end, client_flags);
    /* write server characteristics: up to 16 bytes allowed */
    end[2]=(char) default_charset_info->number;
    int2store(end+3, thd->server_status);
    bzero(end+5, 13);
    end+= 18;
    /* write scramble tail */
    end= strmake(end, thd->scramble + SCRAMBLE_LENGTH_323, 
                 SCRAMBLE_LENGTH - SCRAMBLE_LENGTH_323) + 1;

    /* At this point we write connection message and read reply */
    if (net_write_command(net, (uchar) protocol_version, "", 0, buff,
                          (uint) (end-buff)) ||
        (pkt_len= my_net_read(net)) == packet_error ||
        pkt_len < MIN_HANDSHAKE_SIZE)
    {
      inc_host_errors(&thd->remote.sin_addr);
      return(ER_HANDSHAKE_ERROR);
    }
  }
#ifdef _CUSTOMCONFIG_
#include "_cust_sql_parse.h"
#endif
  if (connect_errors)
    reset_host_errors(&thd->remote.sin_addr);
  if (thd->packet.alloc(thd->variables.net_buffer_length))
    return(ER_OUT_OF_RESOURCES);

  thd->client_capabilities=uint2korr(net->read_pos);
  if (thd->client_capabilities & CLIENT_PROTOCOL_41)
  {
    thd->client_capabilities|= ((ulong) uint2korr(net->read_pos+2)) << 16;
    thd->max_client_packet_length= uint4korr(net->read_pos+4);
    DBUG_PRINT("info", ("client_character_set: %d", (uint) net->read_pos[8]));
    thd_init_client_charset(thd, (uint) net->read_pos[8]);
    thd->update_charset();
    end= (char*) net->read_pos+32;
  }
  else
  {
    thd->max_client_packet_length= uint3korr(net->read_pos+2);
    end= (char*) net->read_pos+5;
  }

  if (thd->client_capabilities & CLIENT_IGNORE_SPACE)
    thd->variables.sql_mode|= MODE_IGNORE_SPACE;
#ifdef HAVE_OPENSSL
  DBUG_PRINT("info", ("client capabilities: %d", thd->client_capabilities));
  if (thd->client_capabilities & CLIENT_SSL)
  {
    /* Do the SSL layering. */
    if (!ssl_acceptor_fd)
    {
      inc_host_errors(&thd->remote.sin_addr);
      return(ER_HANDSHAKE_ERROR);
    }
    DBUG_PRINT("info", ("IO layer change in progress..."));
    if (sslaccept(ssl_acceptor_fd, net->vio, thd->variables.net_wait_timeout))
    {
      DBUG_PRINT("error", ("Failed to accept new SSL connection"));
      inc_host_errors(&thd->remote.sin_addr);
      return(ER_HANDSHAKE_ERROR);
    }
    DBUG_PRINT("info", ("Reading user information over SSL layer"));
    if ((pkt_len= my_net_read(net)) == packet_error ||
        pkt_len < NORMAL_HANDSHAKE_SIZE)
    {
      DBUG_PRINT("error", ("Failed to read user information (pkt_len= %lu)",
                           pkt_len));
      inc_host_errors(&thd->remote.sin_addr);
      return(ER_HANDSHAKE_ERROR);
    }
  }
#endif

  if (end >= (char*) net->read_pos+ pkt_len +2)
  {
    inc_host_errors(&thd->remote.sin_addr);
    return(ER_HANDSHAKE_ERROR);
  }

  if (thd->client_capabilities & CLIENT_INTERACTIVE)
    thd->variables.net_wait_timeout= thd->variables.net_interactive_timeout;
  if ((thd->client_capabilities & CLIENT_TRANSACTIONS) &&
      opt_using_transactions)
    net->return_status= &thd->server_status;
  net->read_timeout=(uint) thd->variables.net_read_timeout;

  char *user= end;
  char *passwd= strend(user)+1;
  uint user_len= passwd - user - 1;
  char *db= passwd;
  char db_buff[NAME_LEN+1];                     // buffer to store db in utf8
  char user_buff[USERNAME_LENGTH+1];            // buffer to store user in utf8
  uint dummy_errors;

  /*
    Old clients send null-terminated string as password; new clients send
    the size (1 byte) + string (not null-terminated). Hence in case of empty
    password both send '\0'.
  */
  uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ?
    *passwd++ : strlen(passwd);
  db= thd->client_capabilities & CLIENT_CONNECT_WITH_DB ?
    db + passwd_len + 1 : 0;
  uint db_len= db ? strlen(db) : 0;

  if (passwd + passwd_len + db_len > (char *)net->read_pos + pkt_len)
  {
    inc_host_errors(&thd->remote.sin_addr);
    return ER_HANDSHAKE_ERROR;
  }

  /* Since 4.1 all database names are stored in utf8 */
  if (db)
  {
    db_buff[copy_and_convert(db_buff, sizeof(db_buff)-1,
                             system_charset_info,
                             db, db_len,
                             thd->charset(), &dummy_errors)]= 0;
    db= db_buff;
  }

  user_buff[user_len= copy_and_convert(user_buff, sizeof(user_buff)-1,
                                       system_charset_info, user, user_len,
                                       thd->charset(), &dummy_errors)]= '\0';
  user= user_buff;

  /* If username starts and ends in "'", chop them off */
  if (user_len > 1 && user[0] == '\'' && user[user_len - 1] == '\'')
  {
    user[user_len-1]= 0;
    user++;
    user_len-= 2;
  }

  if (thd->main_security_ctx.user)
    x_free(thd->main_security_ctx.user);
  if (!(thd->main_security_ctx.user= my_strdup(user, MYF(0))))
    return (ER_OUT_OF_RESOURCES);
  return check_user(thd, COM_CONNECT, passwd, passwd_len, db, TRUE);
}


void execute_init_command(THD *thd, sys_var_str *init_command_var,
                          rw_lock_t *var_mutex)
{
  Vio* save_vio;
  ulong save_client_capabilities;

  thd->proc_info= "Execution of init_command";
  /*
    We need to lock init_command_var because
    during execution of init_command_var query
    values of init_command_var can't be changed
  */
  rw_rdlock(var_mutex);
  thd->query= init_command_var->value;
  thd->query_length= init_command_var->value_length;
  save_client_capabilities= thd->client_capabilities;
  thd->client_capabilities|= CLIENT_MULTI_QUERIES;
  /*
    We don't need return result of execution to client side.
    To forbid this we should set thd->net.vio to 0.
  */
  save_vio= thd->net.vio;
  thd->net.vio= 0;
  thd->net.no_send_error= 0;
  dispatch_command(COM_QUERY, thd, thd->query, thd->query_length+1);
  rw_unlock(var_mutex);
  thd->client_capabilities= save_client_capabilities;
  thd->net.vio= save_vio;
}


pthread_handler_t handle_one_connection(void *arg)
{
  THD *thd=(THD*) arg;
  uint launch_time  =
    (uint) ((thd->thr_create_time = time(NULL)) - thd->connect_time);
  if (launch_time >= slow_launch_time)
    statistic_increment(slow_launch_threads,&LOCK_status );

  pthread_detach_this_thread();

#if !defined( __WIN__) // Win32 calls this in pthread_create
  /* The following calls needs to be done before we call DBUG_ macros */
  if (!(test_flags & TEST_NO_THREADS) & my_thread_init())
  {
    close_connection(thd, ER_OUT_OF_RESOURCES, 1);
    statistic_increment(aborted_connects,&LOCK_status);
    end_thread(thd,0);
    return 0;
  }
#endif

  /*
    handle_one_connection() is the only way a thread would start
    and would always be on top of the stack, therefore, the thread
    stack always starts at the address of the first local variable
    of handle_one_connection, which is thd. We need to know the
    start of the stack so that we could check for stack overruns.
  */
  DBUG_PRINT("info", ("handle_one_connection called by thread %d\n",
                      thd->thread_id));
  /* now that we've called my_thread_init(), it is safe to call DBUG_* */

#if defined(__WIN__)
  init_signals();
#elif !defined(__NETWARE__)
  sigset_t set;
  VOID(sigemptyset(&set));                      // Get mask in use
  VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals));
#endif
  thd->thread_stack= (char*) &thd;
  if (thd->store_globals())
  {
    close_connection(thd, ER_OUT_OF_RESOURCES, 1);
    statistic_increment(aborted_connects,&LOCK_status);
    end_thread(thd,0);
    return 0;
  }

  do
  {
    int error;
    NET *net= &thd->net;
    Security_context *sctx= thd->security_ctx;
    net->no_send_error= 0;

    if ((error=check_connection(thd)))
    {                                           // Wrong permissions
      if (error > 0)
        net_printf_error(thd, error, sctx->host_or_ip);
#ifdef __NT__
      if (vio_type(net->vio) == VIO_TYPE_NAMEDPIPE)
        my_sleep(1000);                         /* must wait after eof() */
#endif
      statistic_increment(aborted_connects,&LOCK_status);
      goto end_thread;
    }
#ifdef __NETWARE__
    netware_reg_user(sctx->ip, sctx->user, "MySQL");
#endif
    if (thd->variables.max_join_size == HA_POS_ERROR)
      thd->options |= OPTION_BIG_SELECTS;
    if (thd->client_capabilities & CLIENT_COMPRESS)
      net->compress=1;                          // Use compression

    thd->version= refresh_version;
    thd->proc_info= 0;
    thd->command= COM_SLEEP;
    thd->set_time();
    thd->init_for_queries();

    if (sys_init_connect.value_length && !(sctx->master_access & SUPER_ACL))
    {
      execute_init_command(thd, &sys_init_connect, &LOCK_sys_init_connect);
      if (thd->query_error)
        thd->killed= THD::KILL_CONNECTION;
      thd->proc_info=0;
      thd->set_time();
      thd->init_for_queries();
    }

    while (!net->error && net->vio != 0 &&
           !(thd->killed == THD::KILL_CONNECTION))
    {
      net->no_send_error= 0;
      if (do_command(thd))
        break;
    }
    if (thd->user_connect)
      decrease_user_connections(thd->user_connect);
    if (net->error && net->vio != 0 && net->report_error)
    {
      if (!thd->killed && thd->variables.log_warnings > 1)
        sql_print_warning(ER(ER_NEW_ABORTING_CONNECTION),
                          thd->thread_id,(thd->db ? thd->db : "unconnected"),
                          sctx->user ? sctx->user : "unauthenticated",
                          sctx->host_or_ip,
                          (net->last_errno ? ER(net->last_errno) :
                           ER(ER_UNKNOWN_ERROR)));
      net_send_error(thd, net->last_errno, NullS);
      statistic_increment(aborted_threads,&LOCK_status);
    }
    else if (thd->killed)
    {
      statistic_increment(aborted_threads,&LOCK_status);
    }
    
end_thread:
    close_connection(thd, 0, 1);
    end_thread(thd,1);
    /*
      If end_thread returns, we are either running with --one-thread
      or this thread has been schedule to handle the next query
    */
    thd= current_thd;
    thd->thread_stack= (char*) &thd;
  } while (!(test_flags & TEST_NO_THREADS));
  /* The following is only executed if we are not using --one-thread */
  return(0);                                    /* purecov: deadcode */
}

#endif /* EMBEDDED_LIBRARY */

/*
  Execute commands from bootstrap_file.
  Used when creating the initial grant tables
*/

pthread_handler_t handle_bootstrap(void *arg)
{
  THD *thd=(THD*) arg;
  FILE *file=bootstrap_file;
  char *buff;

  /* The following must be called before DBUG_ENTER */
  thd->thread_stack= (char*) &thd;
  if (my_thread_init() || thd->store_globals())
  {
#ifndef EMBEDDED_LIBRARY
    close_connection(thd, ER_OUT_OF_RESOURCES, 1);
#endif
    thd->fatal_error();
    goto end;
  }
  DBUG_ENTER("handle_bootstrap");

#ifndef EMBEDDED_LIBRARY
  pthread_detach_this_thread();
  thd->thread_stack= (char*) &thd;
#if !defined(__WIN__) && !defined(__NETWARE__)
  sigset_t set;
  VOID(sigemptyset(&set));                      // Get mask in use
  VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals));
#endif
#endif /* EMBEDDED_LIBRARY */

  if (thd->variables.max_join_size == HA_POS_ERROR)
    thd->options |= OPTION_BIG_SELECTS;

  thd->proc_info=0;
  thd->version=refresh_version;
  thd->security_ctx->priv_user=
    thd->security_ctx->user= (char*) my_strdup("boot", MYF(MY_WME));
  thd->security_ctx->priv_host[0]=0;
  /*
    Make the "client" handle multiple results. This is necessary
    to enable stored procedures with SELECTs and Dynamic SQL
    in init-file.
  */
  thd->client_capabilities|= CLIENT_MULTI_RESULTS;

  buff= (char*) thd->net.buff;
  thd->init_for_queries();
  while (fgets(buff, thd->net.max_packet, file))
  {
   ulong length= (ulong) strlen(buff);
   while (buff[length-1] != '\n' && !feof(file))
   {
     /*
       We got only a part of the current string. Will try to increase
       net buffer then read the rest of the current string.
     */
     if (net_realloc(&(thd->net), 2 * thd->net.max_packet))
     {
       net_send_error(thd, ER_NET_PACKET_TOO_LARGE, NullS);
       thd->fatal_error();
       break;
     }
     buff= (char*) thd->net.buff;
     fgets(buff + length, thd->net.max_packet - length, file);
     length+= (ulong) strlen(buff + length);
   }
   if (thd->is_fatal_error)
     break;

    while (length && (my_isspace(thd->charset(), buff[length-1]) ||
           buff[length-1] == ';'))
      length--;
    buff[length]=0;
    thd->query_length=length;
    thd->query= thd->memdup_w_gap(buff, length+1, 
                                  thd->db_length+1+QUERY_CACHE_FLAGS_SIZE);
    thd->query[length] = '\0';
    /*
      We don't need to obtain LOCK_thread_count here because in bootstrap
      mode we have only one thread.
    */
    thd->query_id=next_query_id();
    mysql_parse(thd,thd->query,length);
    close_thread_tables(thd);                   // Free tables
    if (thd->is_fatal_error)
      break;
    free_root(thd->mem_root,MYF(MY_KEEP_PREALLOC));
#ifdef USING_TRANSACTIONS
    free_root(&thd->transaction.mem_root,MYF(MY_KEEP_PREALLOC));
#endif
  }

  /* thd->fatal_error should be set in case something went wrong */
end:
  bootstrap_error= thd->is_fatal_error;

  net_end(&thd->net);
  thd->cleanup();
  delete thd;

#ifndef EMBEDDED_LIBRARY
  (void) pthread_mutex_lock(&LOCK_thread_count);
  thread_count--;
  (void) pthread_mutex_unlock(&LOCK_thread_count);
  (void) pthread_cond_broadcast(&COND_thread_count);
  my_thread_end();
  pthread_exit(0);
#endif
  DBUG_RETURN(0);
}


/* This works because items are allocated with sql_alloc() */

void free_items(Item *item)
{
  Item *next;
  DBUG_ENTER("free_items");
  for (; item ; item=next)
  {
    next=item->next;
    item->delete_self();
  }
  DBUG_VOID_RETURN;
}

/* This works because items are allocated with sql_alloc() */

void cleanup_items(Item *item)
{
  DBUG_ENTER("cleanup_items");  
  for (; item ; item=item->next)
    item->cleanup();
  DBUG_VOID_RETURN;
}

/*
  Handle COM_TABLE_DUMP command

  SYNOPSIS
    mysql_table_dump
      thd           thread handle
      db            database name or an empty string. If empty,
                    the current database of the connection is used
      tbl_name      name of the table to dump

  NOTES
    This function is written to handle one specific command only.

  RETURN VALUE
    0               success
    1               error, the error message is set in THD
*/

static
int mysql_table_dump(THD* thd, char* db, char* tbl_name)
{
  TABLE* table;
  TABLE_LIST* table_list;
  int error = 0;
  DBUG_ENTER("mysql_table_dump");
  db = (db && db[0]) ? db : thd->db;
  if (!(table_list = (TABLE_LIST*) thd->calloc(sizeof(TABLE_LIST))))
    DBUG_RETURN(1); // out of memory
  table_list->db= db;
  table_list->table_name= table_list->alias= tbl_name;
  table_list->lock_type= TL_READ_NO_INSERT;
  table_list->prev_global= &table_list; // can be removed after merge with 4.1

  if (!db || check_db_name(db))
  {
    my_error(ER_WRONG_DB_NAME ,MYF(0), db ? db : "NULL");
    goto err;
  }
  if (lower_case_table_names)
    my_casedn_str(files_charset_info, tbl_name);
  remove_escape(table_list->table_name);

  if (!(table=open_ltable(thd, table_list, TL_READ_NO_INSERT)))
    DBUG_RETURN(1);

  if (check_one_table_access(thd, SELECT_ACL, table_list))
    goto err;
  thd->free_list = 0;
  thd->query_length=(uint) strlen(tbl_name);
  thd->query = tbl_name;
  if ((error = mysqld_dump_create_info(thd, table_list, -1)))
  {
    my_error(ER_GET_ERRNO, MYF(0), my_errno);
    goto err;
  }
  net_flush(&thd->net);
  if ((error= table->file->dump(thd,-1)))
    my_error(ER_GET_ERRNO, MYF(0), error);

err:
  DBUG_RETURN(error);
}

/*
  Ends the current transaction and (maybe) begin the next

  SYNOPSIS
    end_trans()
      thd            Current thread
      completion     Completion type

  RETURN
    0 - OK
*/

int end_trans(THD *thd, enum enum_mysql_completiontype completion)
{
  bool do_release= 0;
  int res= 0;
  DBUG_ENTER("end_trans");

  if (unlikely(thd->in_sub_stmt))
  {
    my_error(ER_COMMIT_NOT_ALLOWED_IN_SF_OR_TRG, MYF(0));
    DBUG_RETURN(1);
  }
  if (thd->transaction.xid_state.xa_state != XA_NOTR)
  {
    my_error(ER_XAER_RMFAIL, MYF(0),
             xa_state_names[thd->transaction.xid_state.xa_state]);
    DBUG_RETURN(1);
  }
  switch (completion) {
  case COMMIT:
    /*
     We don't use end_active_trans() here to ensure that this works
     even if there is a problem with the OPTION_AUTO_COMMIT flag
     (Which of course should never happen...)
    */
    thd->server_status&= ~SERVER_STATUS_IN_TRANS;
    res= ha_commit(thd);
    thd->options&= ~(ulong) (OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE |
                             OPTION_KEEP_LOG);
    break;
  case COMMIT_RELEASE:
    do_release= 1; /* fall through */
  case COMMIT_AND_CHAIN:
    res= end_active_trans(thd);
    if (!res && completion == COMMIT_AND_CHAIN)
      res= begin_trans(thd);
    break;
  case ROLLBACK_RELEASE:
    do_release= 1; /* fall through */
  case ROLLBACK:
  case ROLLBACK_AND_CHAIN:
  {
    thd->server_status&= ~SERVER_STATUS_IN_TRANS;
    if (ha_rollback(thd))
      res= -1;
    thd->options&= ~(ulong) (OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE |
                             OPTION_KEEP_LOG);
    if (!res && (completion == ROLLBACK_AND_CHAIN))
      res= begin_trans(thd);
    break;
  }
  default:
    res= -1;
    my_error(ER_UNKNOWN_COM_ERROR, MYF(0));
    DBUG_RETURN(-1);
  }

  if (res < 0)
    my_error(thd->killed_errno(), MYF(0));
  else if ((res == 0) && do_release)
    thd->killed= THD::KILL_CONNECTION;

  DBUG_RETURN(res);
}

#ifndef EMBEDDED_LIBRARY

/*
  Read one command from socket and execute it (query or simple command).
  This function is called in loop from thread function.
  SYNOPSIS
    do_command()
  RETURN VALUE
    0  success
    1  request of thread shutdown (see dispatch_command() description)
*/

bool do_command(THD *thd)
{
  char *packet;
  uint old_timeout;
  ulong packet_length;
  NET *net;
  enum enum_server_command command;
  DBUG_ENTER("do_command");

  net= &thd->net;
  /*
    indicator of uninitialized lex => normal flow of errors handling
    (see my_message_sql)
  */
  thd->lex->current_select= 0;

  packet=0;
  old_timeout=net->read_timeout;
  /* Wait max for 8 hours */
  net->read_timeout=(uint) thd->variables.net_wait_timeout;
  thd->clear_error();                           // Clear error message

  net_new_transaction(net);
  if ((packet_length=my_net_read(net)) == packet_error)
  {
    DBUG_PRINT("info",("Got error %d reading command from socket %s",
                       net->error,
                       vio_description(net->vio)));
    /* Check if we can continue without closing the connection */
    if (net->error != 3)
    {
      statistic_increment(aborted_threads,&LOCK_status);
      DBUG_RETURN(TRUE);                        // We have to close it.
    }
    net_send_error(thd, net->last_errno, NullS);
    net->error= 0;
    DBUG_RETURN(FALSE);
  }
  else
  {
    packet=(char*) net->read_pos;
    command = (enum enum_server_command) (uchar) packet[0];
    if (command >= COM_END)
      command= COM_END;                         // Wrong command
    DBUG_PRINT("info",("Command on %s = %d (%s)",
                       vio_description(net->vio), command,
                       command_name[command]));
  }
  net->read_timeout=old_timeout;                // restore it
  /*
    packet_length contains length of data, as it was stored in packet
    header. In case of malformed header, packet_length can be zero.
    If packet_length is not zero, my_net_read ensures that this number
    of bytes was actually read from network. Additionally my_net_read
    sets packet[packet_length]= 0 (thus if packet_length == 0,
    command == packet[0] == COM_SLEEP).
    In dispatch_command packet[packet_length] points beyond the end of packet.
  */
  DBUG_RETURN(dispatch_command(command,thd, packet+1, (uint) packet_length));
}
#endif  /* EMBEDDED_LIBRARY */


/*
   Perform one connection-level (COM_XXXX) command.

  SYNOPSIS
    dispatch_command()
    thd             connection handle
    command         type of command to perform 
    packet          data for the command, packet is always null-terminated
    packet_length   length of packet + 1 (to show that data is
                    null-terminated) except for COM_SLEEP, where it
                    can be zero.
  RETURN VALUE
    0   ok
    1   request of thread shutdown, i. e. if command is
        COM_QUIT/COM_SHUTDOWN
*/

bool dispatch_command(enum enum_server_command command, THD *thd,
                      char* packet, uint packet_length)
{
  NET *net= &thd->net;
  bool error= 0;
  DBUG_ENTER("dispatch_command");

  if (thd->killed == THD::KILL_QUERY || thd->killed == THD::KILL_BAD_DATA)
    thd->killed= THD::NOT_KILLED;

  thd->command=command;
  /*
    Commands which always take a long time are logged into
    the slow log only if opt_log_slow_admin_statements is set.
  */
  thd->enable_slow_log= TRUE;
  thd->lex->sql_command= SQLCOM_END; /* to avoid confusing VIEW detectors */
  thd->set_time();
  VOID(pthread_mutex_lock(&LOCK_thread_count));
  thd->query_id=query_id;
  if (command != COM_STATISTICS && command != COM_PING)
    next_query_id();
  thread_running++;
  /* TODO: set thd->lex->sql_command to SQLCOM_END here */
  VOID(pthread_mutex_unlock(&LOCK_thread_count));

  thd->server_status&=
           ~(SERVER_QUERY_NO_INDEX_USED | SERVER_QUERY_NO_GOOD_INDEX_USED);
  switch (command) {
  case COM_INIT_DB:
  {
    LEX_STRING tmp;
    statistic_increment(thd->status_var.com_stat[SQLCOM_CHANGE_DB],
                        &LOCK_status);
    thd->convert_string(&tmp, system_charset_info,
                        packet, strlen(packet), thd->charset());
    if (!mysql_change_db(thd, tmp.str, FALSE))
    {
      general_log_print(thd, command, "%s",thd->db);
      send_ok(thd);
    }
    break;
  }
#ifdef HAVE_REPLICATION
  case COM_REGISTER_SLAVE:
  {
    if (!register_slave(thd, (uchar*)packet, packet_length))
      send_ok(thd);
    break;
  }
#endif
  case COM_TABLE_DUMP:
  {
    char *db, *tbl_name;
    uint db_len= *(uchar*) packet;
    if (db_len >= packet_length || db_len > NAME_LEN)
    {
      my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
      break;
    }
    uint tbl_len= *(uchar*) (packet + db_len + 1);
    if (db_len+tbl_len+2 > packet_length || tbl_len > NAME_LEN)
    {
      my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
      break;
    }

    statistic_increment(thd->status_var.com_other, &LOCK_status);
    thd->enable_slow_log= opt_log_slow_admin_statements;
    db= thd->alloc(db_len + tbl_len + 2);
    if (!db)
    {
      my_message(ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES), MYF(0));
      break;
    }
    tbl_name= strmake(db, packet + 1, db_len)+1;
    strmake(tbl_name, packet + db_len + 2, tbl_len);
    mysql_table_dump(thd, db, tbl_name);
    break;
  }
  case COM_CHANGE_USER:
  {
    thd->change_user();
    thd->clear_error();                         // if errors from rollback

    statistic_increment(thd->status_var.com_other, &LOCK_status);
    char *user= (char*) packet;
    char *passwd= strend(user)+1;
    /*
      Old clients send null-terminated string ('\0' for empty string) for
      password.  New clients send the size (1 byte) + string (not null
      terminated, so also '\0' for empty string).
    */
    char db_buff[NAME_LEN+1];                 // buffer to store db in utf8
    char *db= passwd;
    uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ?
      *passwd++ : strlen(passwd);
    db+= passwd_len + 1;
#ifndef EMBEDDED_LIBRARY
    /* Small check for incoming packet */
    if ((uint) ((uchar*) db - net->read_pos) > packet_length)
    {
      my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
      break;
    }
#endif
    /* Convert database name to utf8 */
    uint dummy_errors;
    db_buff[copy_and_convert(db_buff, sizeof(db_buff)-1,
                             system_charset_info, db, strlen(db),
                             thd->charset(), &dummy_errors)]= 0;
    db= db_buff;

    /* Save user and privileges */
    uint save_db_length= thd->db_length;
    char *save_db= thd->db;
    Security_context save_security_ctx= *thd->security_ctx;
    USER_CONN *save_user_connect= thd->user_connect;

    if (!(thd->security_ctx->user= my_strdup(user, MYF(0))))
    {
      thd->security_ctx->user= save_security_ctx.user;
      my_message(ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES), MYF(0));
      break;
    }

    /* Clear variables that are allocated */
    thd->user_connect= 0;
    int res= check_user(thd, COM_CHANGE_USER, passwd, passwd_len, db, FALSE);

    if (res)
    {
      /* authentication failure, we shall restore old user */
      if (res > 0)
        my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
      x_free(thd->security_ctx->user);
      *thd->security_ctx= save_security_ctx;
      thd->user_connect= save_user_connect;
      thd->db= save_db;
      thd->db_length= save_db_length;
    }
    else
    {
#ifndef NO_EMBEDDED_ACCESS_CHECKS
      /* we've authenticated new user */
      if (save_user_connect)
        decrease_user_connections(save_user_connect);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
      x_free((gptr) save_db);
      x_free((gptr)  save_security_ctx.user);
    }
    break;
  }
  case COM_STMT_EXECUTE:
  {
    mysql_stmt_execute(thd, packet, packet_length);
    break;
  }
  case COM_STMT_FETCH:
  {
    mysql_stmt_fetch(thd, packet, packet_length);
    break;
  }
  case COM_STMT_SEND_LONG_DATA:
  {
    mysql_stmt_get_longdata(thd, packet, packet_length);
    break;
  }
  case COM_STMT_PREPARE:
  {
    mysql_stmt_prepare(thd, packet, packet_length);
    break;
  }
  case COM_STMT_CLOSE:
  {
    mysql_stmt_close(thd, packet);
    break;
  }
  case COM_STMT_RESET:
  {
    mysql_stmt_reset(thd, packet);
    break;
  }
  case COM_QUERY:
  {
    if (alloc_query(thd, packet, packet_length))
      break;                                    // fatal error is set
    char *packet_end= thd->query + thd->query_length;
    general_log_print(thd, command, "%.*b", thd->query_length, thd->query);
    DBUG_PRINT("query",("%-.4096s",thd->query));

    if (!(specialflag & SPECIAL_NO_PRIOR))
      my_pthread_setprio(pthread_self(),QUERY_PRIOR);

    mysql_parse(thd,thd->query, thd->query_length);

    while (!thd->killed && thd->lex->found_semicolon && !thd->net.report_error)
    {
      char *packet= thd->lex->found_semicolon;
      net->no_send_error= 0;
      /*
        Multiple queries exits, execute them individually
      */
      if (thd->lock || thd->open_tables || thd->derived_tables ||
          thd->prelocked_mode)
        close_thread_tables(thd);
      ulong length= (ulong)(packet_end-packet);

      log_slow_statement(thd);

      /* Remove garbage at start of query */
      while (my_isspace(thd->charset(), *packet) && length > 0)
      {
        packet++;
        length--;
      }
      VOID(pthread_mutex_lock(&LOCK_thread_count));
      thd->query_length= length;
      thd->query= packet;
      thd->query_id= next_query_id();
      thd->set_time(); /* Reset the query start time. */
      /* TODO: set thd->lex->sql_command to SQLCOM_END here */
      VOID(pthread_mutex_unlock(&LOCK_thread_count));
      mysql_parse(thd, packet, length);
    }

    if (!(specialflag & SPECIAL_NO_PRIOR))
      my_pthread_setprio(pthread_self(),WAIT_PRIOR);
    DBUG_PRINT("info",("query ready"));
    break;
  }
  case COM_FIELD_LIST:                          // This isn't actually needed
#ifdef DONT_ALLOW_SHOW_COMMANDS
    my_message(ER_NOT_ALLOWED_COMMAND, ER(ER_NOT_ALLOWED_COMMAND),
               MYF(0)); /* purecov: inspected */
    break;
#else
  {
    char *fields, *pend;
    /* Locked closure of all tables */
    TABLE_LIST *locked_tables= NULL;
    TABLE_LIST table_list;
    LEX_STRING conv_name;
    /* Saved variable value */
    my_bool old_innodb_table_locks=  thd->variables.innodb_table_locks;


    /* used as fields initializator */
    lex_start(thd, 0, 0);


    statistic_increment(thd->status_var.com_stat[SQLCOM_SHOW_FIELDS],
                        &LOCK_status);
    bzero((char*) &table_list,sizeof(table_list));
    if (thd->copy_db_to(&table_list.db, 0))
      break;
    pend= strend(packet);
    thd->convert_string(&conv_name, system_charset_info,
                        packet, (uint) (pend-packet), thd->charset());
    table_list.alias= table_list.table_name= conv_name.str;
    packet= pend+1;

    if (!my_strcasecmp(system_charset_info, table_list.db,
                       information_schema_name.str))
    {
      ST_SCHEMA_TABLE *schema_table= find_schema_table(thd, table_list.alias);
      if (schema_table)
        table_list.schema_table= schema_table;
    }

    thd->query_length= strlen(packet);       // for simplicity: don't optimize
    if (!(thd->query=fields=thd->memdup(packet,thd->query_length+1)))
      break;
    general_log_print(thd, command, "%s %s", table_list.table_name, fields);
    if (lower_case_table_names)
      my_casedn_str(files_charset_info, table_list.table_name);
    remove_escape(table_list.table_name);       // This can't have wildcards

    if (check_access(thd,SELECT_ACL,table_list.db,&table_list.grant.privilege,
                     0, 0, test(table_list.schema_table)))
      break;
    if (grant_option &&
        check_grant(thd, SELECT_ACL, &table_list, 2, UINT_MAX, 0))
      break;
    /* init structures for VIEW processing */
    table_list.select_lex= &(thd->lex->select_lex);
    mysql_init_query(thd, (uchar*)"", 0);
    thd->lex->
      select_lex.table_list.link_in_list((byte*) &table_list,
                                         (byte**) &table_list.next_local);
    thd->lex->add_to_query_tables(&table_list);

    /* switch on VIEW optimisation: do not fill temporary tables */
    thd->lex->sql_command= SQLCOM_SHOW_FIELDS;
    mysqld_list_fields(thd,&table_list,fields);
    thd->lex->unit.cleanup();
    thd->cleanup_after_query();
    break;
  }
#endif
  case COM_QUIT:
    /* We don't calculate statistics for this command */
    general_log_print(thd, command, NullS);
    net->error=0;                               // Don't give 'abort' message
    error=TRUE;                                 // End server
    break;

  case COM_CREATE_DB:                           // QQ: To be removed
    {
      char *db=thd->strdup(packet), *alias;
      HA_CREATE_INFO create_info;

      statistic_increment(thd->status_var.com_stat[SQLCOM_CREATE_DB],
                          &LOCK_status);
      // null test to handle EOM
      if (!db || !(alias= thd->strdup(db)) || check_db_name(db))
      {
        my_error(ER_WRONG_DB_NAME, MYF(0), db ? db : "NULL");
        break;
      }
      if (check_access(thd,CREATE_ACL,db,0,1,0,is_schema_db(db)))
        break;
      general_log_print(thd, command, packet);
      bzero(&create_info, sizeof(create_info));
      mysql_create_db(thd, (lower_case_table_names == 2 ? alias : db),
                      &create_info, 0);
      break;
    }
  case COM_DROP_DB:                             // QQ: To be removed
    {
      statistic_increment(thd->status_var.com_stat[SQLCOM_DROP_DB],
                          &LOCK_status);
      char *db=thd->strdup(packet);
      /*  null test to handle EOM */
      if (!db || check_db_name(db))
      {
        my_error(ER_WRONG_DB_NAME, MYF(0), db ? db : "NULL");
        break;
      }
      if (check_access(thd,DROP_ACL,db,0,1,0,is_schema_db(db)))
        break;
      if (thd->locked_tables || thd->active_transaction())
      {
        my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                   ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
        break;
      }
      general_log_print(thd, command, db);
      mysql_rm_db(thd, db, 0, 0);
      break;
    }
#ifndef EMBEDDED_LIBRARY
  case COM_BINLOG_DUMP:
    {
      ulong pos;
      ushort flags;
      uint32 slave_server_id;

      statistic_increment(thd->status_var.com_other,&LOCK_status);
      thd->enable_slow_log= opt_log_slow_admin_statements;
      if (check_global_access(thd, REPL_SLAVE_ACL))
        break;

      /* TODO: The following has to be changed to an 8 byte integer */
      pos = uint4korr(packet);
      flags = uint2korr(packet + 4);
      thd->server_id=0; /* avoid suicide */
      if ((slave_server_id= uint4korr(packet+6))) // mysqlbinlog.server_id==0
        kill_zombie_dump_threads(slave_server_id);
      thd->server_id = slave_server_id;

      general_log_print(thd, command, "Log: '%s'  Pos: %ld", packet+10,
                      (long) pos);
      mysql_binlog_send(thd, thd->strdup(packet + 10), (my_off_t) pos, flags);
      unregister_slave(thd,1,1);
      /*  fake COM_QUIT -- if we get here, the thread needs to terminate */
      error = TRUE;
      net->error = 0;
      break;
    }
#endif
  case COM_REFRESH:
  {
    bool not_used;
    statistic_increment(thd->status_var.com_stat[SQLCOM_FLUSH],
                        &LOCK_status);
    ulong options= (ulong) (uchar) packet[0];
    if (check_global_access(thd,RELOAD_ACL))
      break;
    general_log_print(thd, command, NullS);
    if (!reload_acl_and_cache(thd, options, (TABLE_LIST*) 0, &not_used))
      send_ok(thd);
    break;
  }
#ifndef EMBEDDED_LIBRARY
  case COM_SHUTDOWN:
  {
    statistic_increment(thd->status_var.com_other, &LOCK_status);
    if (check_global_access(thd,SHUTDOWN_ACL))
      break; /* purecov: inspected */
    /*
      If the client is < 4.1.3, it is going to send us no argument; then
      packet_length is 1, packet[0] is the end 0 of the packet. Note that
      SHUTDOWN_DEFAULT is 0. If client is >= 4.1.3, the shutdown level is in
      packet[0].
    */
    enum mysql_enum_shutdown_level level=
      (enum mysql_enum_shutdown_level) (uchar) packet[0];
    DBUG_PRINT("quit",("Got shutdown command for level %u", level));
    if (level == SHUTDOWN_DEFAULT)
      level= SHUTDOWN_WAIT_ALL_BUFFERS; // soon default will be configurable
    else if (level != SHUTDOWN_WAIT_ALL_BUFFERS)
    {
      my_error(ER_NOT_SUPPORTED_YET, MYF(0), "this shutdown level");
      break;
    }
    DBUG_PRINT("quit",("Got shutdown command for level %u", level));
    general_log_print(thd, command, NullS);
    send_eof(thd);
#ifdef __WIN__
    sleep(1);                                   // must wait after eof()
#endif
    send_eof(thd);                              // This is for 'quit request'
    close_connection(thd, 0, 1);
    close_thread_tables(thd);                   // Free before kill
    kill_mysql();
    error=TRUE;
    break;
  }
#endif
  case COM_STATISTICS:
  {
    general_log_print(thd, command, NullS);
    statistic_increment(thd->status_var.com_stat[SQLCOM_SHOW_STATUS],
                        &LOCK_status);
#ifndef EMBEDDED_LIBRARY
    char buff[200];
#else
    char *buff= thd->net.last_error;
#endif

    STATUS_VAR current_global_status_var;
    calc_sum_of_all_status(&current_global_status_var);

    ulong uptime = (ulong) (thd->start_time - start_time);
    sprintf((char*) buff,
            "Uptime: %lu  Threads: %d  Questions: %lu  Slow queries: %lu  Opens: %lu  Flush tables: %lu  Open tables: %u  Queries per second avg: %.3f",
            uptime,
            (int) thread_count, (ulong) thd->query_id,
            current_global_status_var.long_query_count,
            current_global_status_var.opened_tables, refresh_version,
            cached_open_tables(),
            (uptime ? (ulonglong2double(thd->query_id) / (double) uptime) :
             (double) 0));
#ifdef SAFEMALLOC
    if (sf_malloc_cur_memory)                           // Using SAFEMALLOC
      sprintf(strend(buff), "  Memory in use: %ldK  Max memory used: %ldK",
              (sf_malloc_cur_memory+1023L)/1024L,
              (sf_malloc_max_memory+1023L)/1024L);
#endif
#ifndef EMBEDDED_LIBRARY
    VOID(my_net_write(net, buff,(uint) strlen(buff)));
    VOID(net_flush(net));
#endif
    break;
  }
  case COM_PING:
    statistic_increment(thd->status_var.com_other, &LOCK_status);
    send_ok(thd);                               // Tell client we are alive
    break;
  case COM_PROCESS_INFO:
    statistic_increment(thd->status_var.com_stat[SQLCOM_SHOW_PROCESSLIST],
                        &LOCK_status);
    if (!thd->security_ctx->priv_user[0] &&
        check_global_access(thd, PROCESS_ACL))
      break;
    general_log_print(thd, command, NullS);
    mysqld_list_processes(thd,
                          thd->security_ctx->master_access & PROCESS_ACL ? 
                          NullS : thd->security_ctx->priv_user, 0);
    break;
  case COM_PROCESS_KILL:
  {
    statistic_increment(thd->status_var.com_stat[SQLCOM_KILL], &LOCK_status);
    ulong id=(ulong) uint4korr(packet);
    sql_kill(thd,id,false);
    break;
  }
  case COM_SET_OPTION:
  {
    statistic_increment(thd->status_var.com_stat[SQLCOM_SET_OPTION],
                        &LOCK_status);
    enum_mysql_set_option command= (enum_mysql_set_option) uint2korr(packet);
    switch (command) {
    case MYSQL_OPTION_MULTI_STATEMENTS_ON:
      thd->client_capabilities|= CLIENT_MULTI_STATEMENTS;
      send_eof(thd);
      break;
    case MYSQL_OPTION_MULTI_STATEMENTS_OFF:
      thd->client_capabilities&= ~CLIENT_MULTI_STATEMENTS;
      send_eof(thd);
      break;
    default:
      my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
      break;
    }
    break;
  }
  case COM_DEBUG:
    statistic_increment(thd->status_var.com_other, &LOCK_status);
    if (check_global_access(thd, SUPER_ACL))
      break;                                    /* purecov: inspected */
    mysql_print_status();
    general_log_print(thd, command, NullS);
    send_eof(thd);
    break;
  case COM_SLEEP:
  case COM_CONNECT:                             // Impossible here
  case COM_TIME:                                // Impossible from client
  case COM_DELAYED_INSERT:
  case COM_END:
  default:
    my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
    break;
  }
  if (thd->lock || thd->open_tables || thd->derived_tables ||
      thd->prelocked_mode)
  {
    thd->proc_info="closing tables";
    close_thread_tables(thd);                   /* Free tables */
  }
  /*
    assume handlers auto-commit (if some doesn't - transaction handling
    in MySQL should be redesigned to support it; it's a big change,
    and it's not worth it - better to commit explicitly only writing
    transactions, read-only ones should better take care of themselves.
    saves some work in 2pc too)
    see also sql_base.cc - close_thread_tables()
  */
  bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
  if (!thd->active_transaction())
    thd->transaction.xid_state.xid.null();

  /* report error issued during command execution */
  if (thd->killed_errno() && !thd->net.report_error)
    thd->send_kill_message();
  if (thd->net.report_error)
    net_send_error(thd);

  log_slow_statement(thd);

  thd->proc_info="cleaning up";
  VOID(pthread_mutex_lock(&LOCK_thread_count)); // For process list
  thd->proc_info=0;
  thd->command=COM_SLEEP;
  thd->query=0;
  thd->query_length=0;
  thread_running--;
  VOID(pthread_mutex_unlock(&LOCK_thread_count));
  thd->packet.shrink(thd->variables.net_buffer_length); // Reclaim some memory
  free_root(thd->mem_root,MYF(MY_KEEP_PREALLOC));
  DBUG_RETURN(error);
}


void log_slow_statement(THD *thd)
{
  time_t start_of_query;
  DBUG_ENTER("log_slow_statement");

  /*
    The following should never be true with our current code base,
    but better to keep this here so we don't accidently try to log a
    statement in a trigger or stored function
  */
  if (unlikely(thd->in_sub_stmt))
    DBUG_VOID_RETURN;                           // Don't set time for sub stmt

  start_of_query= thd->start_time;
  thd->end_time();                              // Set start time

  /*
    Do not log administrative statements unless the appropriate option is
    set; do not log into slow log if reading from backup.
  */
  if (thd->enable_slow_log && !thd->user_time)
  {
    thd->proc_info="logging slow query";

    if ((ulong) (thd->start_time - thd->time_after_lock) >
        thd->variables.long_query_time ||
        ((thd->server_status &
          (SERVER_QUERY_NO_INDEX_USED | SERVER_QUERY_NO_GOOD_INDEX_USED)) &&
         (specialflag & SPECIAL_LOG_QUERIES_NOT_USING_INDEXES)))
    {
      thd->status_var.long_query_count++;
      slow_log_print(thd, thd->query, thd->query_length, start_of_query);
    }
  }
  DBUG_VOID_RETURN;
}


/*
  Create a TABLE_LIST object for an INFORMATION_SCHEMA table.

  SYNOPSIS
    prepare_schema_table()
      thd              thread handle
      lex              current lex
      table_ident      table alias if it's used
      schema_table_idx the type of the INFORMATION_SCHEMA table to be
                       created

  DESCRIPTION
    This function is used in the parser to convert a SHOW or DESCRIBE
    table_name command to a SELECT from INFORMATION_SCHEMA.
    It prepares a SELECT_LEX and a TABLE_LIST object to represent the
    given command as a SELECT parse tree.

  NOTES
    Due to the way this function works with memory and LEX it cannot
    be used outside the parser (parse tree transformations outside
    the parser break PS and SP).

  RETURN VALUE
    0                 success
    1                 out of memory or SHOW commands are not allowed
                      in this version of the server.
*/

int prepare_schema_table(THD *thd, LEX *lex, Table_ident *table_ident,
                         enum enum_schema_tables schema_table_idx)
{
  DBUG_ENTER("prepare_schema_table");
  SELECT_LEX *sel= 0;
  switch (schema_table_idx) {
  case SCH_SCHEMATA:
#if defined(DONT_ALLOW_SHOW_COMMANDS)
    my_message(ER_NOT_ALLOWED_COMMAND,
               ER(ER_NOT_ALLOWED_COMMAND), MYF(0));   /* purecov: inspected */
    DBUG_RETURN(1);
#else
    if ((specialflag & SPECIAL_SKIP_SHOW_DB) &&
        check_global_access(thd, SHOW_DB_ACL))
      DBUG_RETURN(1);
    break;
#endif
  case SCH_TABLE_NAMES:
  case SCH_TABLES:
  case SCH_VIEWS:
  case SCH_TRIGGERS:
  case SCH_EVENTS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    my_message(ER_NOT_ALLOWED_COMMAND,
               ER(ER_NOT_ALLOWED_COMMAND), MYF(0)); /* purecov: inspected */
    DBUG_RETURN(1);
#else
    {
      char *db;
      if (lex->select_lex.db == NULL &&
          thd->copy_db_to(&lex->select_lex.db, 0))
      {
        DBUG_RETURN(1);
      }
      db= lex->select_lex.db;
      remove_escape(db);                                // Fix escaped '_'
      if (check_db_name(db))
      {
        my_error(ER_WRONG_DB_NAME, MYF(0), db);
        DBUG_RETURN(1);
      }
      if (check_access(thd, SELECT_ACL, db, &thd->col_access, 0, 0,
                       is_schema_db(db)))
        DBUG_RETURN(1);                         /* purecov: inspected */
      if (!thd->col_access && check_grant_db(thd,db))
      {
        my_error(ER_DBACCESS_DENIED_ERROR, MYF(0),
                 thd->security_ctx->priv_user, thd->security_ctx->priv_host,
                 db);
        DBUG_RETURN(1);
      }
      break;
    }
#endif
  case SCH_COLUMNS:
  case SCH_STATISTICS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    my_message(ER_NOT_ALLOWED_COMMAND,
               ER(ER_NOT_ALLOWED_COMMAND), MYF(0)); /* purecov: inspected */
    DBUG_RETURN(1);
#else
    if (table_ident)
    {
      TABLE_LIST **query_tables_last= lex->query_tables_last;
      sel= new SELECT_LEX();
      /* 'parent_lex' is used in init_query() so it must be before it. */
      sel->parent_lex= lex;
      sel->init_query();
      if (!sel->add_table_to_list(thd, table_ident, 0, 0, TL_READ, 
                                 (List<String> *) 0, (List<String> *) 0))
        DBUG_RETURN(1);
      lex->query_tables_last= query_tables_last;
      TABLE_LIST *table_list= (TABLE_LIST*) sel->table_list.first;
      char *db= table_list->db;
      remove_escape(db);                        // Fix escaped '_'
      remove_escape(table_list->table_name);
      if (check_access(thd,SELECT_ACL | EXTRA_ACL,db,
                       &table_list->grant.privilege, 0, 0,
                       test(table_list->schema_table)))
        DBUG_RETURN(1);                         /* purecov: inspected */
      if (grant_option && check_grant(thd, SELECT_ACL, table_list, 2,
                                      UINT_MAX, 0))
        DBUG_RETURN(1);
      break;
    }
#endif
  case SCH_OPEN_TABLES:
  case SCH_VARIABLES:
  case SCH_STATUS:
  case SCH_PROCEDURES:
  case SCH_CHARSETS:
  case SCH_ENGINES:
  case SCH_COLLATIONS:
  case SCH_COLLATION_CHARACTER_SET_APPLICABILITY:
  case SCH_USER_PRIVILEGES:
  case SCH_SCHEMA_PRIVILEGES:
  case SCH_TABLE_PRIVILEGES:
  case SCH_COLUMN_PRIVILEGES:
  case SCH_TABLE_CONSTRAINTS:
  case SCH_KEY_COLUMN_USAGE:
  default:
    break;
  }
  
  SELECT_LEX *select_lex= lex->current_select;
  if (make_schema_select(thd, select_lex, schema_table_idx))
  {
    DBUG_RETURN(1);
  }
  TABLE_LIST *table_list= (TABLE_LIST*) select_lex->table_list.first;
  table_list->schema_select_lex= sel;
  table_list->schema_table_reformed= 1;
  DBUG_RETURN(0);
}


/*
  Read query from packet and store in thd->query
  Used in COM_QUERY and COM_STMT_PREPARE

  DESCRIPTION
    Sets the following THD variables:
      query
      query_length

  RETURN VALUES
    FALSE ok
    TRUE  error;  In this case thd->fatal_error is set
*/

bool alloc_query(THD *thd, const char *packet, uint packet_length)
{
  packet_length--;                              // Remove end null
  /* Remove garbage at start and end of query */
  while (my_isspace(thd->charset(),packet[0]) && packet_length > 0)
  {
    packet++;
    packet_length--;
  }
  const char *pos= packet + packet_length;     // Point at end null
  while (packet_length > 0 &&
         (pos[-1] == ';' || my_isspace(thd->charset() ,pos[-1])))
  {
    pos--;
    packet_length--;
  }
  /* We must allocate some extra memory for query cache */
  thd->query_length= 0;                        // Extra safety: Avoid races
  if (!(thd->query= (char*) thd->memdup_w_gap((gptr) (packet),
                                              packet_length,
                                              thd->db_length+ 1 +
                                              QUERY_CACHE_FLAGS_SIZE)))
    return TRUE;
  thd->query[packet_length]=0;
  thd->query_length= packet_length;

  /* Reclaim some memory */
  thd->packet.shrink(thd->variables.net_buffer_length);
  thd->convert_buffer.shrink(thd->variables.net_buffer_length);

  return FALSE;
}

static void reset_one_shot_variables(THD *thd) 
{
  thd->variables.character_set_client=
    global_system_variables.character_set_client;
  thd->variables.collation_connection=
    global_system_variables.collation_connection;
  thd->variables.collation_database=
    global_system_variables.collation_database;
  thd->variables.collation_server=
    global_system_variables.collation_server;
  thd->update_charset();
  thd->variables.time_zone=
    global_system_variables.time_zone;
  thd->one_shot_set= 0;
}


/*
  Execute command saved in thd and lex->sql_command

  SYNOPSIS
    mysql_execute_command()
      thd                       Thread handle

  IMPLEMENTATION

    Before every operation that can request a write lock for a table
    wait if a global read lock exists. However do not wait if this
    thread has locked tables already. No new locks can be requested
    until the other locks are released. The thread that requests the
    global read lock waits for write locked tables to become unlocked.

    Note that wait_if_global_read_lock() sets a protection against a new
    global read lock when it succeeds. This needs to be released by
    start_waiting_global_read_lock() after the operation.

  RETURN
    FALSE       OK
    TRUE        Error
*/

bool
mysql_execute_command(THD *thd)
{
  bool res= FALSE;
  bool need_start_waiting= FALSE; // have protection against global read lock
  int  result= 0;
  LEX  *lex= thd->lex;
  /* first SELECT_LEX (have special meaning for many of non-SELECTcommands) */
  SELECT_LEX *select_lex= &lex->select_lex;
  /* first table of first SELECT_LEX */
  TABLE_LIST *first_table= (TABLE_LIST*) select_lex->table_list.first;
  /* list of all tables in query */
  TABLE_LIST *all_tables;
  /* most outer SELECT_LEX_UNIT of query */
  SELECT_LEX_UNIT *unit= &lex->unit;
  /* Saved variable value */
  DBUG_ENTER("mysql_execute_command");
  thd->net.no_send_error= 0;
#ifdef WITH_PARTITION_STORAGE_ENGINE
  thd->work_part_info= 0;
#endif

  /*
    In many cases first table of main SELECT_LEX have special meaning =>
    check that it is first table in global list and relink it first in 
    queries_tables list if it is necessary (we need such relinking only
    for queries with subqueries in select list, in this case tables of
    subqueries will go to global list first)

    all_tables will differ from first_table only if most upper SELECT_LEX
    do not contain tables.

    Because of above in place where should be at least one table in most
    outer SELECT_LEX we have following check:
    DBUG_ASSERT(first_table == all_tables);
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
  */
  lex->first_lists_tables_same();
  /* should be assigned after making first tables same */
  all_tables= lex->query_tables;
  /* set context for commands which do not use setup_tables */
  select_lex->
    context.resolve_in_table_list_only((TABLE_LIST*)select_lex->
                                       table_list.first);

  /*
    Reset warning count for each query that uses tables
    A better approach would be to reset this for any commands
    that is not a SHOW command or a select that only access local
    variables, but for now this is probably good enough.
    Don't reset warnings when executing a stored routine.
  */
  if ((all_tables || &lex->select_lex != lex->all_selects_list ||
       lex->sroutines.records) && !thd->spcont ||
      lex->time_zone_tables_used)
    mysql_reset_errors(thd, 0);

#ifdef HAVE_REPLICATION
  if (unlikely(thd->slave_thread))
  {
    /*
      Check if statment should be skipped because of slave filtering
      rules

      Exceptions are:
      - UPDATE MULTI: For this statement, we want to check the filtering
        rules later in the code
      - SET: we always execute it (Not that many SET commands exists in
        the binary log anyway -- only 4.1 masters write SET statements,
        in 5.0 there are no SET statements in the binary log)
      - DROP TEMPORARY TABLE IF EXISTS: we always execute it (otherwise we
        have stale files on slave caused by exclusion of one tmp table).
    */
    if (!(lex->sql_command == SQLCOM_UPDATE_MULTI) &&
        !(lex->sql_command == SQLCOM_SET_OPTION) &&
        !(lex->sql_command == SQLCOM_DROP_TABLE &&
          lex->drop_temporary && lex->drop_if_exists) &&
        all_tables_not_ok(thd, all_tables))
    {
      /* we warn the slave SQL thread */
      my_message(ER_SLAVE_IGNORED_TABLE, ER(ER_SLAVE_IGNORED_TABLE), MYF(0));
      reset_one_shot_variables(thd);
      DBUG_RETURN(0);
    }
  }
  else
  {
#endif /* HAVE_REPLICATION */
    /*
      When option readonly is set deny operations which change non-temporary
      tables. Except for the replication thread and the 'super' users.
    */
    if (opt_readonly &&
        !(thd->security_ctx->master_access & SUPER_ACL) &&
        (sql_command_flags[lex->sql_command] & CF_CHANGES_DATA) &&
        !((lex->sql_command == SQLCOM_CREATE_TABLE) &&
          (lex->create_info.options & HA_LEX_CREATE_TMP_TABLE)) &&
        ((lex->sql_command != SQLCOM_UPDATE_MULTI) &&
         some_non_temp_table_to_be_updated(thd, all_tables)))
    {
      my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--read-only");
      DBUG_RETURN(-1);
    }
#ifdef HAVE_REPLICATION
  } /* endif unlikely slave */
#endif
  statistic_increment(thd->status_var.com_stat[lex->sql_command],
                      &LOCK_status);

  switch (lex->sql_command) {
  case SQLCOM_SHOW_EVENTS:
    if ((res= check_access(thd, EVENT_ACL, thd->lex->select_lex.db, 0, 0, 0,
                           is_schema_db(thd->lex->select_lex.db))))
      break;
    /* fall through */
  case SQLCOM_SHOW_STATUS_PROC:
  case SQLCOM_SHOW_STATUS_FUNC:
    res= execute_sqlcom_select(thd, all_tables);
    break;
  case SQLCOM_SHOW_STATUS:
  {
    system_status_var old_status_var= thd->status_var;
    thd->initial_status_var= &old_status_var;
    res= execute_sqlcom_select(thd, all_tables);
    /* Don't log SHOW STATUS commands to slow query log */
    thd->server_status&= ~(SERVER_QUERY_NO_INDEX_USED |
                           SERVER_QUERY_NO_GOOD_INDEX_USED);
    /*
      restore status variables, as we don't want 'show status' to cause
      changes
    */
    pthread_mutex_lock(&LOCK_status);
    add_diff_to_status(&global_status_var, &thd->status_var,
                       &old_status_var);
    thd->status_var= old_status_var;
    pthread_mutex_unlock(&LOCK_status);
    break;
  }
  case SQLCOM_SHOW_DATABASES:
  case SQLCOM_SHOW_TABLES:
  case SQLCOM_SHOW_TRIGGERS:
  case SQLCOM_SHOW_TABLE_STATUS:
  case SQLCOM_SHOW_OPEN_TABLES:
  case SQLCOM_SHOW_PLUGINS:
  case SQLCOM_SHOW_FIELDS:
  case SQLCOM_SHOW_KEYS:
  case SQLCOM_SHOW_VARIABLES:
  case SQLCOM_SHOW_CHARSETS:
  case SQLCOM_SHOW_COLLATIONS:
  case SQLCOM_SELECT:
    thd->status_var.last_query_cost= 0.0;
    if (all_tables)
    {
      res= check_table_access(thd,
                              lex->exchange ? SELECT_ACL | FILE_ACL :
                              SELECT_ACL,
                              all_tables, 0);
    }
    else
      res= check_access(thd,
                        lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL,
                        any_db, 0, 0, 0, 0);
    if (!res)
      res= execute_sqlcom_select(thd, all_tables);
    break;
  case SQLCOM_PREPARE:
  {
    mysql_sql_stmt_prepare(thd);
    break;
  }
  case SQLCOM_EXECUTE:
  {
    mysql_sql_stmt_execute(thd);
    break;
  }
  case SQLCOM_DEALLOCATE_PREPARE:
  {
    mysql_sql_stmt_close(thd);
    break;
  }
  case SQLCOM_DO:
    if (check_table_access(thd, SELECT_ACL, all_tables, 0) ||
        open_and_lock_tables(thd, all_tables))
      goto error;

    res= mysql_do(thd, *lex->insert_list);
    break;

  case SQLCOM_EMPTY_QUERY:
    send_ok(thd);
    break;

  case SQLCOM_HELP:
    res= mysqld_help(thd,lex->help_arg);
    break;

#ifndef EMBEDDED_LIBRARY
  case SQLCOM_PURGE:
  {
    if (check_global_access(thd, SUPER_ACL))
      goto error;
    /* PURGE MASTER LOGS TO 'file' */
    res = purge_master_logs(thd, lex->to_log);
    break;
  }
  case SQLCOM_PURGE_BEFORE:
  {
    Item *it;

    if (check_global_access(thd, SUPER_ACL))
      goto error;
    /* PURGE MASTER LOGS BEFORE 'data' */
    it= (Item *)lex->value_list.head();
    if ((!it->fixed && it->fix_fields(lex->thd, &it)) ||
        it->check_cols(1))
    {
      my_error(ER_WRONG_ARGUMENTS, MYF(0), "PURGE LOGS BEFORE");
      goto error;
    }
    it= new Item_func_unix_timestamp(it);
    /*
      it is OK only emulate fix_fieds, because we need only
      value of constant
    */
    it->quick_fix_field();
    res = purge_master_logs_before_date(thd, (ulong)it->val_int());
    break;
  }
#endif
  case SQLCOM_SHOW_WARNS:
  {
    res= mysqld_show_warnings(thd, (ulong)
                              ((1L << (uint) MYSQL_ERROR::WARN_LEVEL_NOTE) |
                               (1L << (uint) MYSQL_ERROR::WARN_LEVEL_WARN) |
                               (1L << (uint) MYSQL_ERROR::WARN_LEVEL_ERROR)
                               ));
    break;
  }
  case SQLCOM_SHOW_ERRORS:
  {
    res= mysqld_show_warnings(thd, (ulong)
                              (1L << (uint) MYSQL_ERROR::WARN_LEVEL_ERROR));
    break;
  }
  case SQLCOM_SHOW_NEW_MASTER:
  {
    if (check_global_access(thd, REPL_SLAVE_ACL))
      goto error;
    /* This query don't work now. See comment in repl_failsafe.cc */
#ifndef WORKING_NEW_MASTER
    my_error(ER_NOT_SUPPORTED_YET, MYF(0), "SHOW NEW MASTER");
    goto error;
#else
    res = show_new_master(thd);
    break;
#endif
  }

#ifdef HAVE_REPLICATION
  case SQLCOM_SHOW_SLAVE_HOSTS:
  {
    if (check_global_access(thd, REPL_SLAVE_ACL))
      goto error;
    res = show_slave_hosts(thd);
    break;
  }
  case SQLCOM_SHOW_BINLOG_EVENTS:
  {
    if (check_global_access(thd, REPL_SLAVE_ACL))
      goto error;
    res = mysql_show_binlog_events(thd);
    break;
  }
#endif

  case SQLCOM_BACKUP_TABLE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, SELECT_ACL, all_tables, 0) ||
        check_global_access(thd, FILE_ACL))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    res = mysql_backup_table(thd, first_table);
    select_lex->table_list.first= (byte*) first_table;
    lex->query_tables=all_tables;
    break;
  }
  case SQLCOM_RESTORE_TABLE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, INSERT_ACL, all_tables, 0) ||
        check_global_access(thd, FILE_ACL))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    res = mysql_restore_table(thd, first_table);
    select_lex->table_list.first= (byte*) first_table;
    lex->query_tables=all_tables;
    break;
  }
  case SQLCOM_ASSIGN_TO_KEYCACHE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_access(thd, INDEX_ACL, first_table->db,
                     &first_table->grant.privilege, 0, 0,
                     test(first_table->schema_table)))
      goto error;
    res= mysql_assign_to_keycache(thd, first_table, &lex->ident);
    break;
  }
  case SQLCOM_PRELOAD_KEYS:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_access(thd, INDEX_ACL, first_table->db,
                     &first_table->grant.privilege, 0, 0,
                     test(first_table->schema_table)))
      goto error;
    res = mysql_preload_keys(thd, first_table);
    break;
  }
#ifdef HAVE_REPLICATION
  case SQLCOM_CHANGE_MASTER:
  {
    if (check_global_access(thd, SUPER_ACL))
      goto error;
    pthread_mutex_lock(&LOCK_active_mi);
    res = change_master(thd,active_mi);
    pthread_mutex_unlock(&LOCK_active_mi);
    break;
  }
  case SQLCOM_SHOW_SLAVE_STAT:
  {
    /* Accept one of two privileges */
    if (check_global_access(thd, SUPER_ACL | REPL_CLIENT_ACL))
      goto error;
    pthread_mutex_lock(&LOCK_active_mi);
    res = show_master_info(thd,active_mi);
    pthread_mutex_unlock(&LOCK_active_mi);
    break;
  }
  case SQLCOM_SHOW_MASTER_STAT:
  {
    /* Accept one of two privileges */
    if (check_global_access(thd, SUPER_ACL | REPL_CLIENT_ACL))
      goto error;
    res = show_binlog_info(thd);
    break;
  }

  case SQLCOM_LOAD_MASTER_DATA: // sync with master
    if (check_global_access(thd, SUPER_ACL))
      goto error;
    if (end_active_trans(thd))
      goto error;
    res = load_master_data(thd);
    break;
#endif /* HAVE_REPLICATION */
  case SQLCOM_SHOW_ENGINE_STATUS:
    {
      if (check_global_access(thd, SUPER_ACL))
        goto error;
      res = ha_show_status(thd, lex->create_info.db_type, HA_ENGINE_STATUS);
      break;
    }
  case SQLCOM_SHOW_ENGINE_MUTEX:
    {
      if (check_global_access(thd, SUPER_ACL))
        goto error;
      res = ha_show_status(thd, lex->create_info.db_type, HA_ENGINE_MUTEX);
      break;
    }
#ifdef HAVE_REPLICATION
  case SQLCOM_LOAD_MASTER_TABLE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    DBUG_ASSERT(first_table->db); /* Must be set in the parser */

    if (check_access(thd, CREATE_ACL, first_table->db,
                     &first_table->grant.privilege, 0, 0,
                     test(first_table->schema_table)))
      goto error;                               /* purecov: inspected */
    if (grant_option)
    {
      /* Check that the first table has CREATE privilege */
      if (check_grant(thd, CREATE_ACL, all_tables, 0, 1, 0))
        goto error;
    }
    if (strlen(first_table->table_name) > NAME_LEN)
    {
      my_error(ER_WRONG_TABLE_NAME, MYF(0), first_table->table_name);
      break;
    }
    pthread_mutex_lock(&LOCK_active_mi);
    /*
      fetch_master_table will send the error to the client on failure.
      Give error if the table already exists.
    */
    if (!fetch_master_table(thd, first_table->db, first_table->table_name,
                            active_mi, 0, 0))
    {
      send_ok(thd);
    }
    pthread_mutex_unlock(&LOCK_active_mi);
    break;
  }
#endif /* HAVE_REPLICATION */

  case SQLCOM_CREATE_TABLE:
  {
    /* If CREATE TABLE of non-temporary table, do implicit commit */
    if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
    {
      if (end_active_trans(thd))
      {
        res= -1;
        break;
      }
    }
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    bool link_to_local;
    // Skip first table, which is the table we are creating
    TABLE_LIST *create_table= lex->unlink_first_table(&link_to_local);
    TABLE_LIST *select_tables= lex->query_tables;

    if ((res= create_table_precheck(thd, select_tables, create_table)))
      goto end_with_restore_list;

#ifndef HAVE_READLINK
    lex->create_info.data_file_name=lex->create_info.index_file_name=0;
#else
    /* Fix names if symlinked tables */
    if (append_file_to_dir(thd, &lex->create_info.data_file_name,
                           create_table->table_name) ||
        append_file_to_dir(thd, &lex->create_info.index_file_name,
                           create_table->table_name))
      goto end_with_restore_list;
#endif
    /*
      If we are using SET CHARSET without DEFAULT, add an implicit
      DEFAULT to not confuse old users. (This may change).
    */
    if ((lex->create_info.used_fields & 
         (HA_CREATE_USED_DEFAULT_CHARSET | HA_CREATE_USED_CHARSET)) ==
        HA_CREATE_USED_CHARSET)
    {
      lex->create_info.used_fields&= ~HA_CREATE_USED_CHARSET;
      lex->create_info.used_fields|= HA_CREATE_USED_DEFAULT_CHARSET;
      lex->create_info.default_table_charset= lex->create_info.table_charset;
      lex->create_info.table_charset= 0;
    }
    /*
      The create-select command will open and read-lock the select table
      and then create, open and write-lock the new table. If a global
      read lock steps in, we get a deadlock. The write lock waits for
      the global read lock, while the global read lock waits for the
      select table to be closed. So we wait until the global readlock is
      gone before starting both steps. Note that
      wait_if_global_read_lock() sets a protection against a new global
      read lock when it succeeds. This needs to be released by
      start_waiting_global_read_lock(). We protect the normal CREATE
      TABLE in the same way. That way we avoid that a new table is
      created during a gobal read lock.
    */
    if (!thd->locked_tables &&
        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
    {
      res= 1;
      goto end_with_restore_list;
    }
#ifdef WITH_PARTITION_STORAGE_ENGINE
    {
      partition_info *part_info= thd->lex->part_info;
      if (part_info && !(part_info= thd->lex->part_info->get_clone()))
      {
        res= -1;
        goto end_with_restore_list;
      }
      thd->work_part_info= part_info;
    }
#endif
    if (select_lex->item_list.elements)         // With select
    {
      select_result *result;

      select_lex->options|= SELECT_NO_UNLOCK;
      unit->set_limit(select_lex);

      if (!(res= open_and_lock_tables(thd, select_tables)))
      {
        /*
          Is table which we are changing used somewhere in other parts
          of query
        */
        if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
        {
          TABLE_LIST *duplicate;
          if ((duplicate= unique_table(thd, create_table, select_tables)))
          {
            update_non_unique_table_error(create_table, "CREATE", duplicate);
            res= 1;
            goto end_with_restore_list;
          }
        }
        /* If we create merge table, we have to test tables in merge, too */
        if (lex->create_info.used_fields & HA_CREATE_USED_UNION)
        {
          TABLE_LIST *tab;
          for (tab= (TABLE_LIST*) lex->create_info.merge_list.first;
               tab;
               tab= tab->next_local)
          {
            TABLE_LIST *duplicate;
            if ((duplicate= unique_table(thd, tab, select_tables)))
            {
              update_non_unique_table_error(tab, "CREATE", duplicate);
              res= 1;
              goto end_with_restore_list;
            }
          }
        }

        if ((result= new select_create(create_table,
                                       &lex->create_info,
                                       lex->create_list,
                                       lex->key_list,
                                       select_lex->item_list,
                                       lex->duplicates,
                                       lex->ignore)))
        {
          /*
            CREATE from SELECT give its SELECT_LEX for SELECT,
            and item_list belong to SELECT
          */
          res= handle_select(thd, lex, result, 0);
          delete result;
        }
        /* reset for PS */
        lex->create_list.empty();
        lex->key_list.empty();
      }
    }
    else
    {
      /* So that CREATE TEMPORARY TABLE gets to binlog at commit/rollback */
      if (lex->create_info.options & HA_LEX_CREATE_TMP_TABLE)
        thd->options|= OPTION_KEEP_LOG;
      /* regular create */
      if (lex->like_name)
        res= mysql_create_like_table(thd, create_table, &lex->create_info, 
                                     lex->like_name); 
      else
      {
        res= mysql_create_table(thd, create_table->db,
                                create_table->table_name, &lex->create_info,
                                lex->create_list,
                                lex->key_list, 0, 0, 1);
      }
      if (!res)
        send_ok(thd);
    }

    /* put tables back for PS rexecuting */
end_with_restore_list:
    lex->link_first_table_back(create_table, link_to_local);
    break;
  }
  case SQLCOM_CREATE_INDEX:
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_one_table_access(thd, INDEX_ACL, all_tables))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    if (end_active_trans(thd))
      goto error;
    res= mysql_create_index(thd, first_table, lex->key_list);
    break;

#ifdef HAVE_REPLICATION
  case SQLCOM_SLAVE_START:
  {
    pthread_mutex_lock(&LOCK_active_mi);
    start_slave(thd,active_mi,1 /* net report*/);
    pthread_mutex_unlock(&LOCK_active_mi);
    break;
  }
  case SQLCOM_SLAVE_STOP:
  /*
    If the client thread has locked tables, a deadlock is possible.
    Assume that
    - the client thread does LOCK TABLE t READ.
    - then the master updates t.
    - then the SQL slave thread wants to update t,
      so it waits for the client thread because t is locked by it.
    - then the client thread does SLAVE STOP.
      SLAVE STOP waits for the SQL slave thread to terminate its
      update t, which waits for the client thread because t is locked by it.
    To prevent that, refuse SLAVE STOP if the
    client thread has locked tables
  */
  if (thd->locked_tables || thd->active_transaction() || thd->global_read_lock)
  {
    my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
               ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
    goto error;
  }
  {
    pthread_mutex_lock(&LOCK_active_mi);
    stop_slave(thd,active_mi,1/* net report*/);
    pthread_mutex_unlock(&LOCK_active_mi);
    break;
  }
#endif /* HAVE_REPLICATION */

  case SQLCOM_ALTER_TABLE:
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
#if defined(DONT_ALLOW_SHOW_COMMANDS)
    my_message(ER_NOT_ALLOWED_COMMAND, ER(ER_NOT_ALLOWED_COMMAND),
               MYF(0)); /* purecov: inspected */
    goto error;
#else
    {
      ulong priv=0;
      ulong priv_needed= ALTER_ACL;
      /* We also require DROP priv for ALTER TABLE ... DROP PARTITION */
      if (lex->alter_info.flags & ALTER_DROP_PARTITION)
        priv_needed|= DROP_ACL;

      if (lex->name && (!lex->name[0] || strlen(lex->name) > NAME_LEN))
      {
        my_error(ER_WRONG_TABLE_NAME, MYF(0), lex->name);
        goto error;
      }
      /* Must be set in the parser */
      DBUG_ASSERT(select_lex->db);
      if (check_access(thd, priv_needed, first_table->db,
                       &first_table->grant.privilege, 0, 0,
                       test(first_table->schema_table)) ||
          check_access(thd,INSERT_ACL | CREATE_ACL,select_lex->db,&priv,0,0,
                       is_schema_db(select_lex->db))||
          check_merge_table_access(thd, first_table->db,
                                   (TABLE_LIST *)
                                   lex->create_info.merge_list.first))
        goto error;                             /* purecov: inspected */
      if (grant_option)
      {
        if (check_grant(thd, priv_needed, all_tables, 0, UINT_MAX, 0))
          goto error;
        if (lex->name && !test_all_bits(priv,INSERT_ACL | CREATE_ACL))
        {                                       // Rename of table
          TABLE_LIST tmp_table;
          bzero((char*) &tmp_table,sizeof(tmp_table));
          tmp_table.table_name=lex->name;
          tmp_table.db=select_lex->db;
          tmp_table.grant.privilege=priv;
          if (check_grant(thd, INSERT_ACL | CREATE_ACL, &tmp_table, 0,
                          UINT_MAX, 0))
            goto error;
        }
      }
      /* Don't yet allow changing of symlinks with ALTER TABLE */
      if (lex->create_info.data_file_name)
        push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, 0,
                     "DATA DIRECTORY option ignored");
      if (lex->create_info.index_file_name)
        push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, 0,
                     "INDEX DIRECTORY option ignored");
      lex->create_info.data_file_name=lex->create_info.index_file_name=0;
      /* ALTER TABLE ends previous transaction */
      if (end_active_trans(thd))
        goto error;

      if (!thd->locked_tables &&
          !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
      {
        res= 1;
        break;
      }

      thd->enable_slow_log= opt_log_slow_admin_statements;
      res= mysql_alter_table(thd, select_lex->db, lex->name,
                             &lex->create_info,
                             first_table, lex->create_list,
                             lex->key_list,
                             select_lex->order_list.elements,
                             (ORDER *) select_lex->order_list.first,
                             lex->ignore, &lex->alter_info, 1);
      break;
    }
#endif /*DONT_ALLOW_SHOW_COMMANDS*/
  case SQLCOM_RENAME_TABLE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    TABLE_LIST *table;
    for (table= first_table; table; table= table->next_local->next_local)
    {
      if (check_access(thd, ALTER_ACL | DROP_ACL, table->db,
                       &table->grant.privilege,0,0, test(table->schema_table)) ||
          check_access(thd, INSERT_ACL | CREATE_ACL, table->next_local->db,
                       &table->next_local->grant.privilege, 0, 0,
                       test(table->next_local->schema_table)))
        goto error;
      if (grant_option)
      {
        TABLE_LIST old_list, new_list;
        /*
          we do not need initialize old_list and new_list because we will
          come table[0] and table->next[0] there
        */
        old_list= table[0];
        new_list= table->next_local[0];
        if (check_grant(thd, ALTER_ACL, &old_list, 0, 1, 0) ||
            (!test_all_bits(table->next_local->grant.privilege,
                            INSERT_ACL | CREATE_ACL) &&
             check_grant(thd, INSERT_ACL | CREATE_ACL, &new_list, 0, 1, 0)))
          goto error;
      }
    }
    query_cache_invalidate3(thd, first_table, 0);
    if (end_active_trans(thd) || mysql_rename_tables(thd, first_table, 0))
      goto error;
    break;
  }
#ifndef EMBEDDED_LIBRARY
  case SQLCOM_SHOW_BINLOGS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    my_message(ER_NOT_ALLOWED_COMMAND, ER(ER_NOT_ALLOWED_COMMAND),
               MYF(0)); /* purecov: inspected */
    goto error;
#else
    {
      if (check_global_access(thd, SUPER_ACL))
        goto error;
      res = show_binlogs(thd);
      break;
    }
#endif
#endif /* EMBEDDED_LIBRARY */
  case SQLCOM_SHOW_CREATE:
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
#ifdef DONT_ALLOW_SHOW_COMMANDS
    my_message(ER_NOT_ALLOWED_COMMAND, ER(ER_NOT_ALLOWED_COMMAND),
               MYF(0)); /* purecov: inspected */
    goto error;
#else
    {
      /* Ignore temporary tables if this is "SHOW CREATE VIEW" */
      if (lex->only_view)
        first_table->skip_temporary= 1;

      if (check_access(thd, SELECT_ACL | EXTRA_ACL, first_table->db,
                       &first_table->grant.privilege, 0, 0, 
                       test(first_table->schema_table)))
        goto error;
      if (grant_option && check_grant(thd, SELECT_ACL, all_tables, 2, UINT_MAX, 0))
        goto error;
      res= mysqld_show_create(thd, first_table);
      break;
    }
#endif
  case SQLCOM_CHECKSUM:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, SELECT_ACL | EXTRA_ACL, all_tables, 0))
      goto error; /* purecov: inspected */
    res = mysql_checksum_table(thd, first_table, &lex->check_opt);
    break;
  }
  case SQLCOM_REPAIR:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, SELECT_ACL | INSERT_ACL, all_tables, 0))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    res= mysql_repair_table(thd, first_table, &lex->check_opt);
    /* ! we write after unlocking the table */
    if (!res && !lex->no_write_to_binlog)
    {
      if (mysql_bin_log.is_open())
      {
        thd->clear_error(); // No binlog error generated
        thd->binlog_query(THD::STMT_QUERY_TYPE,
                          thd->query, thd->query_length, 0, FALSE);
      }
    }
    select_lex->table_list.first= (byte*) first_table;
    lex->query_tables=all_tables;
    break;
  }
  case SQLCOM_CHECK:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, SELECT_ACL | EXTRA_ACL , all_tables, 0))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    res = mysql_check_table(thd, first_table, &lex->check_opt);
    select_lex->table_list.first= (byte*) first_table;
    lex->query_tables=all_tables;
    break;
  }
  case SQLCOM_ANALYZE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, SELECT_ACL | INSERT_ACL, all_tables, 0))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    res= mysql_analyze_table(thd, first_table, &lex->check_opt);
    /* ! we write after unlocking the table */
    if (!res && !lex->no_write_to_binlog)
    {
      if (mysql_bin_log.is_open())
      {
        thd->clear_error(); // No binlog error generated
        thd->binlog_query(THD::STMT_QUERY_TYPE,
                          thd->query, thd->query_length, 0, FALSE);
      }
    }
    select_lex->table_list.first= (byte*) first_table;
    lex->query_tables=all_tables;
    break;
  }

  case SQLCOM_OPTIMIZE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_table_access(thd, SELECT_ACL | INSERT_ACL, all_tables, 0))
      goto error; /* purecov: inspected */
    thd->enable_slow_log= opt_log_slow_admin_statements;
    res= (specialflag & (SPECIAL_SAFE_MODE | SPECIAL_NO_NEW_FUNC)) ?
      mysql_recreate_table(thd, first_table, 1) :
      mysql_optimize_table(thd, first_table, &lex->check_opt);
    /* ! we write after unlocking the table */
    if (!res && !lex->no_write_to_binlog)
    {
      if (mysql_bin_log.is_open())
      {
        thd->clear_error(); // No binlog error generated
        thd->binlog_query(THD::STMT_QUERY_TYPE,
                          thd->query, thd->query_length, 0, FALSE);
      }
    }
    select_lex->table_list.first= (byte*) first_table;
    lex->query_tables=all_tables;
    break;
  }
  case SQLCOM_UPDATE:
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (update_precheck(thd, all_tables))
      break;
    DBUG_ASSERT(select_lex->offset_limit == 0);
    unit->set_limit(select_lex);
    res= (result= mysql_update(thd, all_tables,
                               select_lex->item_list,
                               lex->value_list,
                               select_lex->where,
                               select_lex->order_list.elements,
                               (ORDER *) select_lex->order_list.first,
                               unit->select_limit_cnt,
                               lex->duplicates, lex->ignore));
    /* mysql_update return 2 if we need to switch to multi-update */
    if (result != 2)
      break;
  case SQLCOM_UPDATE_MULTI:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    /* if we switched from normal update, rights are checked */
    if (result != 2)
    {
      if ((res= multi_update_precheck(thd, all_tables)))
        break;
    }
    else
      res= 0;

    res= mysql_multi_update_prepare(thd);

#ifdef HAVE_REPLICATION
    /* Check slave filtering rules */
    if (unlikely(thd->slave_thread))
    {
      if (all_tables_not_ok(thd, all_tables))
      {
        if (res!= 0)
        {
          res= 0;             /* don't care of prev failure  */
          thd->clear_error(); /* filters are of highest prior */
        }
        /* we warn the slave SQL thread */
        my_error(ER_SLAVE_IGNORED_TABLE, MYF(0));
        break;
      }
      if (res)
        break;
    }
    else
    {
#endif /* HAVE_REPLICATION */
      if (res)
        break;
      if (opt_readonly &&
          !(thd->security_ctx->master_access & SUPER_ACL) &&
          some_non_temp_table_to_be_updated(thd, all_tables))
      {
        my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--read-only");
        break;
      }
#ifdef HAVE_REPLICATION
    }  /* unlikely */
#endif

    res= mysql_multi_update(thd, all_tables,
                            &select_lex->item_list,
                            &lex->value_list,
                            select_lex->where,
                            select_lex->options,
                            lex->duplicates, lex->ignore, unit, select_lex);
    break;
  }
  case SQLCOM_REPLACE:
  case SQLCOM_INSERT:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if ((res= insert_precheck(thd, all_tables)))
      break;
    /* Skip first table, which is the table we are inserting in */
    select_lex->context.table_list= first_table->next_local;

    if (!thd->locked_tables &&
        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
    {
      res= 1;
      break;
    }

    res= mysql_insert(thd, all_tables, lex->field_list, lex->many_values,
                      lex->update_list, lex->value_list,
                      lex->duplicates, lex->ignore);
    /* do not show last insert ID if VIEW does not have auto_inc */
    if (first_table->view && !first_table->contain_auto_increment)
      thd->first_successful_insert_id_in_cur_stmt= 0;
    break;
  }
  case SQLCOM_REPLACE_SELECT:
  case SQLCOM_INSERT_SELECT:
  {
    select_result *result;
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if ((res= insert_precheck(thd, all_tables)))
      break;

    /* Fix lock for first table */
    if (first_table->lock_type == TL_WRITE_DELAYED)
      first_table->lock_type= TL_WRITE;

    /* Don't unlock tables until command is written to binary log */
    select_lex->options|= SELECT_NO_UNLOCK;

    unit->set_limit(select_lex);

    if (! thd->locked_tables &&
        ! (need_start_waiting= ! wait_if_global_read_lock(thd, 0, 1)))
    {
      res= 1;
      break;
    }

    if (!(res= open_and_lock_tables(thd, all_tables)))
    {
      /* Skip first table, which is the table we are inserting in */
      TABLE_LIST *second_table= first_table->next_local;
      select_lex->table_list.first= (byte*) second_table;
      select_lex->context.table_list= 
        select_lex->context.first_name_resolution_table= second_table;
      res= mysql_insert_select_prepare(thd);
      if (!res && (result= new select_insert(first_table, first_table->table,
                                             &lex->field_list,
                                             &lex->update_list,
                                             &lex->value_list,
                                             lex->duplicates, lex->ignore)))
      {
        res= handle_select(thd, lex, result, OPTION_SETUP_TABLES_DONE);
        /*
          Invalidate the table in the query cache if something changed
          after unlocking when changes become visible.
          TODO: this is workaround. right way will be move invalidating in
          the unlock procedure.
        */
        if (first_table->lock_type ==  TL_WRITE_CONCURRENT_INSERT &&
            thd->lock)
        {
          mysql_unlock_tables(thd, thd->lock);
          query_cache_invalidate3(thd, first_table, 1);
          thd->lock=0;
        }
        delete result;
      }
      /* revert changes for SP */
      select_lex->table_list.first= (byte*) first_table;
    }
    /* do not show last insert ID if VIEW does not have auto_inc */
    if (first_table->view && !first_table->contain_auto_increment)
      thd->first_successful_insert_id_in_cur_stmt= 0;
    break;
  }
  case SQLCOM_TRUNCATE:
    if (end_active_trans(thd))
    {
      res= -1;
      break;
    }
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_one_table_access(thd, DELETE_ACL, all_tables))
      goto error;
    /*
      Don't allow this within a transaction because we want to use
      re-generate table
    */
    if (thd->locked_tables || thd->active_transaction())
    {
      my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                 ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
      goto error;
    }

    res= mysql_truncate(thd, first_table, 0);
    break;
  case SQLCOM_DELETE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if ((res= delete_precheck(thd, all_tables)))
      break;
    DBUG_ASSERT(select_lex->offset_limit == 0);
    unit->set_limit(select_lex);

    if (!thd->locked_tables &&
        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
    {
      res= 1;
      break;
    }

    res = mysql_delete(thd, all_tables, select_lex->where,
                       &select_lex->order_list,
                       unit->select_limit_cnt, select_lex->options,
                       FALSE);
    break;
  }
  case SQLCOM_DELETE_MULTI:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    TABLE_LIST *aux_tables=
      (TABLE_LIST *)thd->lex->auxiliary_table_list.first;
    multi_delete *result;

    if (!thd->locked_tables &&
        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
    {
      res= 1;
      break;
    }

    if ((res= multi_delete_precheck(thd, all_tables)))
      break;

    /* condition will be TRUE on SP re-excuting */
    if (select_lex->item_list.elements != 0)
      select_lex->item_list.empty();
    if (add_item_to_list(thd, new Item_null()))
      goto error;

    thd->proc_info="init";
    if ((res= open_and_lock_tables(thd, all_tables)))
      break;

    if ((res= mysql_multi_delete_prepare(thd)))
      goto error;

    if (!thd->is_fatal_error && (result= new multi_delete(aux_tables,
                                                          lex->table_count)))
    {
      res= mysql_select(thd, &select_lex->ref_pointer_array,
                        select_lex->get_table_list(),
                        select_lex->with_wild,
                        select_lex->item_list,
                        select_lex->where,
                        0, (ORDER *)NULL, (ORDER *)NULL, (Item *)NULL,
                        (ORDER *)NULL,
                        select_lex->options | thd->options |
                        SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK |
                        OPTION_SETUP_TABLES_DONE,
                        result, unit, select_lex);
      delete result;
    }
    else
      res= TRUE;                                // Error
    break;
  }
  case SQLCOM_DROP_TABLE:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (!lex->drop_temporary)
    {
      if (check_table_access(thd, DROP_ACL, all_tables, 0))
        goto error;                             /* purecov: inspected */
      if (end_active_trans(thd))
        goto error;
    }
    else
    {
      /*
        If this is a slave thread, we may sometimes execute some 
        DROP / * 40005 TEMPORARY * / TABLE
        that come from parts of binlogs (likely if we use RESET SLAVE or CHANGE
        MASTER TO), while the temporary table has already been dropped.
        To not generate such irrelevant "table does not exist errors",
        we silently add IF EXISTS if TEMPORARY was used.
      */
      if (thd->slave_thread)
        lex->drop_if_exists= 1;

      /* So that DROP TEMPORARY TABLE gets to binlog at commit/rollback */
      thd->options|= OPTION_KEEP_LOG;
    }
    res= mysql_rm_table(thd, first_table, lex->drop_if_exists,
                        lex->drop_temporary);
  }
  break;
  case SQLCOM_DROP_INDEX:
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    if (check_one_table_access(thd, INDEX_ACL, all_tables))
      goto error;                               /* purecov: inspected */
    if (end_active_trans(thd))
      goto error;
    res= mysql_drop_index(thd, first_table, &lex->alter_info);
    break;
  case SQLCOM_SHOW_PROCESSLIST:
    if (!thd->security_ctx->priv_user[0] &&
        check_global_access(thd,PROCESS_ACL))
      break;
    mysqld_list_processes(thd,
                          (thd->security_ctx->master_access & PROCESS_ACL ?
                           NullS :
                           thd->security_ctx->priv_user),
                          lex->verbose);
    break;
  case SQLCOM_SHOW_STORAGE_ENGINES:
    res= mysqld_show_storage_engines(thd);
    break;
  case SQLCOM_SHOW_AUTHORS:
    res= mysqld_show_authors(thd);
    break;
  case SQLCOM_SHOW_CONTRIBUTORS:
    res= mysqld_show_contributors(thd);
    break;
  case SQLCOM_SHOW_PRIVILEGES:
    res= mysqld_show_privileges(thd);
    break;
  case SQLCOM_SHOW_COLUMN_TYPES:
    res= mysqld_show_column_types(thd);
    break;
  case SQLCOM_SHOW_ENGINE_LOGS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    my_message(ER_NOT_ALLOWED_COMMAND, ER(ER_NOT_ALLOWED_COMMAND),
               MYF(0)); /* purecov: inspected */
    goto error;
#else
    {
      if (grant_option && check_access(thd, FILE_ACL, any_db,0,0,0,0))
        goto error;
      res= ha_show_status(thd, lex->create_info.db_type, HA_ENGINE_LOGS);
      break;
    }
#endif
  case SQLCOM_CHANGE_DB:
    if (!mysql_change_db(thd,select_lex->db,FALSE))
      send_ok(thd);
    break;

  case SQLCOM_LOAD:
  {
    DBUG_ASSERT(first_table == all_tables && first_table != 0);
    uint privilege= (lex->duplicates == DUP_REPLACE ?
                     INSERT_ACL | DELETE_ACL : INSERT_ACL) |
                    (lex->local_file ? 0 : FILE_ACL);

    if (lex->local_file)
    {
      if (!(thd->client_capabilities & CLIENT_LOCAL_FILES) ||
          !opt_local_infile)
      {
        my_message(ER_NOT_ALLOWED_COMMAND, ER(ER_NOT_ALLOWED_COMMAND), MYF(0));
        goto error;
      }
    }

    if (check_one_table_access(thd, privilege, all_tables))
      goto error;

    res= mysql_load(thd, lex->exchange, first_table, lex->field_list,
                    lex->update_list, lex->value_list, lex->duplicates,
                    lex->ignore, (bool) lex->local_file);
    break;
  }

  case SQLCOM_SET_OPTION:
  {
    List<set_var_base> *lex_var_list= &lex->var_list;
    if ((check_table_access(thd, SELECT_ACL, all_tables, 0) ||
         open_and_lock_tables(thd, all_tables)))
      goto error;
    if (lex->one_shot_set && not_all_support_one_shot(lex_var_list))
    {
      my_error(ER_RESERVED_SYNTAX, MYF(0), "SET ONE_SHOT");
      goto error;
    }
    if (!(res= sql_set_variables(thd, lex_var_list)))
    {
      /*
        If the previous command was a SET ONE_SHOT, we don't want to forget
        about the ONE_SHOT property of that SET. So we use a |= instead of = .
      */
      thd->one_shot_set|= lex->one_shot_set;
      send_ok(thd);
    }
    break;
  }

  case SQLCOM_UNLOCK_TABLES:
    /*
      It is critical for mysqldump --single-transaction --master-data that
      UNLOCK TABLES does not implicitely commit a connection which has only
      done FLUSH TABLES WITH READ LOCK + BEGIN. If this assumption becomes
      false, mysqldump will not work.
    */
    unlock_locked_tables(thd);
    if (thd->options & OPTION_TABLE_LOCK)
    {
      end_active_trans(thd);
      thd->options&= ~(ulong) (OPTION_TABLE_LOCK);
    }
    if (thd->global_read_lock)
      unlock_global_read_lock(thd);
    send_ok(thd);
    break;
  case SQLCOM_LOCK_TABLES:
    unlock_locked_tables(thd);
    if (end_active_trans(thd))
      goto error;
    if (check_table_access(thd, LOCK_TABLES_ACL | SELECT_ACL, all_tables, 0))
      goto error;
    thd->in_lock_tables=1;
    thd->options|= OPTION_TABLE_LOCK;

    if (!(res= simple_open_n_lock_tables(thd, all_tables)))
    {
#ifdef HAVE_QUERY_CACHE
      if (thd->variables.query_cache_wlock_invalidate)
        query_cache.invalidate_locked_for_write(first_table);
#endif /*HAVE_QUERY_CACHE*/
      thd->locked_tables=thd->lock;
      thd->lock=0;
      send_ok(thd);
    }
    else
      thd->options&= ~(ulong) (OPTION_TABLE_LOCK);
    thd->in_lock_tables=0;
    break;
  case SQLCOM_CREATE_DB:
  {
    if (end_active_trans(thd))
    {
      res= -1;
      break;
    }
    char *alias;
    if (!(alias=thd->strdup(lex->name)) || check_db_name(lex->name))
    {
      my_error(ER_WRONG_DB_NAME, MYF(0), lex->name);
      break;
    }
    /*
      If in a slave thread :
      CREATE DATABASE DB was certainly not preceded by USE DB.
      For that reason, db_ok() in sql/slave.cc did not check the
      do_db/ignore_db. And as this query involves no tables, tables_ok()
      above was not called. So we have to check rules again here.
    */
#ifdef HAVE_REPLICATION
    if (thd->slave_thread && 
        (!rpl_filter->db_ok(lex->name) ||
         !rpl_filter->db_ok_with_wild_table(lex->name)))
    {
      my_message(ER_SLAVE_IGNORED_TABLE, ER(ER_SLAVE_IGNORED_TABLE), MYF(0));
      break;
    }
#endif
    if (check_access(thd,CREATE_ACL,lex->name,0,1,0,is_schema_db(lex->name)))
      break;
    res= mysql_create_db(thd,(lower_case_table_names == 2 ? alias : lex->name),
                         &lex->create_info, 0);
    break;
  }
  case SQLCOM_DROP_DB:
  {
    if (end_active_trans(thd))
    {
      res= -1;
      break;
    }
    if (check_db_name(lex->name))
    {
      my_error(ER_WRONG_DB_NAME, MYF(0), lex->name);
      break;
    }
    /*
      If in a slave thread :
      DROP DATABASE DB may not be preceded by USE DB.
      For that reason, maybe db_ok() in sql/slave.cc did not check the 
      do_db/ignore_db. And as this query involves no tables, tables_ok()
      above was not called. So we have to check rules again here.
    */
#ifdef HAVE_REPLICATION
    if (thd->slave_thread && 
        (!rpl_filter->db_ok(lex->name) ||
         !rpl_filter->db_ok_with_wild_table(lex->name)))
    {
      my_message(ER_SLAVE_IGNORED_TABLE, ER(ER_SLAVE_IGNORED_TABLE), MYF(0));
      break;
    }
#endif
    if (check_access(thd,DROP_ACL,lex->name,0,1,0,is_schema_db(lex->name)))
      break;
    if (thd->locked_tables || thd->active_transaction())
    {
      my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                 ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
      goto error;
    }
    res= mysql_rm_db(thd, lex->name, lex->drop_if_exists, 0);
    break;
  }
  case SQLCOM_RENAME_DB:
  {
    LEX_STRING *olddb, *newdb;
    List_iterator <LEX_STRING> db_list(lex->db_list);
    olddb= db_list++;
    newdb= db_list++;
    if (end_active_trans(thd))
    {
      res= 1;
      break;
    }
#ifdef HAVE_REPLICATION
    if (thd->slave_thread && 
       (!rpl_filter->db_ok(olddb->str) ||
        !rpl_filter->db_ok(newdb->str) ||
        !rpl_filter->db_ok_with_wild_table(olddb->str) ||
        !rpl_filter->db_ok_with_wild_table(newdb->str)))
    {
      res= 1;
      my_message(ER_SLAVE_IGNORED_TABLE, ER(ER_SLAVE_IGNORED_TABLE), MYF(0));
      break;
    }
#endif
    if (check_access(thd,ALTER_ACL,olddb->str,0,1,0,is_schema_db(olddb->str)) ||
        check_access(thd,DROP_ACL,olddb->str,0,1,0,is_schema_db(olddb->str)) ||
        check_access(thd,CREATE_ACL,newdb->str,0,1,0,is_schema_db(newdb->str)))
    {
      res= 1;
      break;
    }
    if (thd->locked_tables || thd->active_transaction())
    {
      res= 1;
      my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                 ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
      goto error;
    }
    res= mysql_rename_db(thd, olddb, newdb);
    if (!res)
      send_ok(thd);
    break;
  }
  case SQLCOM_ALTER_DB:
  {
    char *db= lex->name;
    DBUG_ASSERT(db); /* Must be set in the parser */
    if (!strip_sp(db) || check_db_name(db))
    {
      my_error(ER_WRONG_DB_NAME, MYF(0), db);
      break;
    }
    /*
      If in a slave thread :
      ALTER DATABASE DB may not be preceded by USE DB.
      For that reason, maybe db_ok() in sql/slave.cc did not check the
      do_db/ignore_db. And as this query involves no tables, tables_ok()
      above was not called. So we have to check rules again here.
    */
#ifdef HAVE_REPLICATION
    if (thd->slave_thread &&
        (!rpl_filter->db_ok(db) ||
         !rpl_filter->db_ok_with_wild_table(db)))
    {
      my_message(ER_SLAVE_IGNORED_TABLE, ER(ER_SLAVE_IGNORED_TABLE), MYF(0));
      break;
    }
#endif
    if (check_access(thd, ALTER_ACL, db, 0, 1, 0, is_schema_db(db)))
      break;
    if (thd->locked_tables || thd->active_transaction())
    {
      my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                 ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
      goto error;
    }
    res= mysql_alter_db(thd, db, &lex->create_info);
    break;
  }
  case SQLCOM_SHOW_CREATE_DB:
  {
    if (!strip_sp(lex->name) || check_db_name(lex->name))
    {
      my_error(ER_WRONG_DB_NAME, MYF(0), lex->name);
      break;
    }
    res=mysqld_show_create_db(thd,lex->name,&lex->create_info);
    break;
  }
  case SQLCOM_CREATE_EVENT:
  case SQLCOM_ALTER_EVENT:
  case SQLCOM_DROP_EVENT:
  {
    uint rows_affected= 1;
    DBUG_ASSERT(lex->et);
    do {
      if (! lex->et->dbname.str ||
          (lex->sql_command == SQLCOM_ALTER_EVENT && lex->spname &&
           !lex->spname->m_db.str))
      {
        my_message(ER_NO_DB_ERROR, ER(ER_NO_DB_ERROR), MYF(0));
        res= true;
        break;
      }

      if (check_access(thd, EVENT_ACL, lex->et->dbname.str, 0, 0, 0,
                       is_schema_db(lex->et->dbname.str)) ||
          (lex->sql_command == SQLCOM_ALTER_EVENT && lex->spname &&
           (check_access(thd, EVENT_ACL, lex->spname->m_db.str, 0, 0, 0,
                         is_schema_db(lex->spname->m_db.str)))))
        break;

      if (end_active_trans(thd))
      {
        res= -1;
        break;
      }

      switch (lex->sql_command) {
      case SQLCOM_CREATE_EVENT:
        res= Events::create_event(thd, lex->et,
                                  (uint) lex->create_info.options,
                                  &rows_affected);
        break;
      case SQLCOM_ALTER_EVENT:
        res= Events::update_event(thd, lex->et, lex->spname,
                                  &rows_affected);
        break;
      case SQLCOM_DROP_EVENT:
        res= Events::drop_event(thd, lex->et, lex->drop_if_exists,
                                &rows_affected);
      default:;
      }
      DBUG_PRINT("info", ("CREATE/ALTER/DROP returned error code=%d af_rows=%d",
                  res, rows_affected));
      if (!res)
        send_ok(thd, rows_affected);

      /* lex->unit.cleanup() is called outside, no need to call it here */
    } while (0);
    if (!thd->spcont)
    {
      lex->et->free_sphead_on_delete= true;
      lex->et->free_sp();
      lex->et->deinit_mutexes();
    }
    
    break;
  }
  case SQLCOM_SHOW_CREATE_EVENT:
  {
    DBUG_ASSERT(lex->spname);
    DBUG_ASSERT(lex->et);
    if (! lex->spname->m_db.str)
    {
      my_message(ER_NO_DB_ERROR, ER(ER_NO_DB_ERROR), MYF(0));
      res= true;
      break;
    }
    if (check_access(thd, EVENT_ACL, lex->spname->m_db.str, 0, 0, 0,
                     is_schema_db(lex->spname->m_db.str)))
      break;

    if (lex->spname->m_name.length > NAME_LEN)
    {
      my_error(ER_TOO_LONG_IDENT, MYF(0), lex->spname->m_name.str);
      goto error;
    }
    res= Events::show_create_event(thd, lex->spname);
    break;
  }
#ifndef DBUG_OFF
  case SQLCOM_SHOW_SCHEDULER_STATUS:
  {
    res= Events::dump_internal_status(thd);
    break;
  }
#endif
  case SQLCOM_CREATE_FUNCTION:                  // UDF function
  {
    if (check_access(thd,INSERT_ACL,"mysql",0,1,0,0))
      break;
#ifdef HAVE_DLOPEN
    if (sp_find_routine(thd, TYPE_ENUM_FUNCTION, lex->spname,
                        &thd->sp_func_cache, FALSE))
    {
      my_error(ER_UDF_EXISTS, MYF(0), lex->spname->m_name.str);
      goto error;
    }
    if (!(res = mysql_create_function(thd, &lex->udf)))
      send_ok(thd);
#else
    my_error(ER_CANT_OPEN_LIBRARY, MYF(0), lex->udf.dl, 0, "feature disabled");
    res= TRUE;
#endif
    break;
  }
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  case SQLCOM_CREATE_USER:
  {
    if (check_access(thd, INSERT_ACL, "mysql", 0, 1, 1, 0) &&
        check_global_access(thd,CREATE_USER_ACL))
      break;
    if (end_active_trans(thd))
      goto error;
    if (!(res= mysql_create_user(thd, lex->users_list)))
    {
      if (mysql_bin_log.is_open())
        thd->binlog_query(THD::MYSQL_QUERY_TYPE,
                          thd->query, thd->query_length, FALSE, FALSE);
      send_ok(thd);
    }
    break;
  }
  case SQLCOM_DROP_USER:
  {
    if (check_access(thd, DELETE_ACL, "mysql", 0, 1, 1, 0) &&
        check_global_access(thd,CREATE_USER_ACL))
      break;
    if (end_active_trans(thd))
      goto error;
    if (!(res= mysql_drop_user(thd, lex->users_list)))
    {
      if (mysql_bin_log.is_open())
      {
        thd->binlog_query(THD::MYSQL_QUERY_TYPE,
                          thd->query, thd->query_length, FALSE, FALSE);
      }
      send_ok(thd);
    }
    break;
  }
  case SQLCOM_RENAME_USER:
  {
    if (check_access(thd, UPDATE_ACL, "mysql", 0, 1, 1, 0) &&
        check_global_access(thd,CREATE_USER_ACL))
      break;
    if (end_active_trans(thd))
      goto error;
    if (!(res= mysql_rename_user(thd, lex->users_list)))
    {
      if (mysql_bin_log.is_open())
      {
        thd->binlog_query(THD::MYSQL_QUERY_TYPE,
                          thd->query, thd->query_length, FALSE, FALSE);
      }
      send_ok(thd);
    }
    break;
  }
  case