sql_parse.cc

/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */

#ifdef EMBEDDED_LIBRARY
#define net_read_timeout net_read_timeout1
#define net_write_timeout net_write_timeout1
#endif

#include "mysql_priv.h"
#include "sql_acl.h"
#include "sql_repl.h"
#include "repl_failsafe.h"
#include <m_ctype.h>
#include <thr_alarm.h>
#include <myisam.h>
#include <my_dir.h>
#include <assert.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 */
#define SCRAMBLE_LENGTH 8


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

static int check_for_max_user_connections(const char *user, const char *host, uint max);
static void decrease_user_connections(const char *user, const char *host);
static bool check_db_used(THD *thd,TABLE_LIST *tables);
static bool check_merge_table_access(THD *thd, char *db, TABLE_LIST *tables);
static bool check_dup(const char *db, const char *name, TABLE_LIST *tables);
static void mysql_init_query(THD *thd);
static void remove_escape(char *name);
static void refresh_status(void);
static bool append_file_to_dir(THD *thd, char **filename_ptr,
			       char *table_name);
static bool create_total_list(THD *thd, LEX *lex, TABLE_LIST **result);

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

const char *command_name[]={
  "Sleep", "Quit", "Init DB", "Query", "Field List", "Create DB",
  "Drop DB", "Refresh", "Shutdown", "Statistics", "Processlist",
  "Connect","Kill","Debug","Ping","Time","Delayed_insert","Change user",
  "Binlog Dump","Table Dump",  "Connect Out", "Register Slave"
};

bool volatile abort_slave = 0;

#ifdef HAVE_OPENSSL
extern struct st_VioSSLAcceptorFd * ssl_acceptor_fd;
#endif /* HAVE_OPENSSL */

#ifdef __WIN__
static void  test_signal(int sig_ptr)
{
#if !defined( DBUG_OFF)
  MessageBox(NULL,"Test signal","DBUG",MB_OK);
#endif
#if defined(OS2)
  fprintf(stderr, "Test signal %d\n", sig_ptr);
  fflush(stderr);
#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

inline bool end_active_trans(THD *thd)
{
  int error=0;
  if (thd->options & (OPTION_NOT_AUTO_COMMIT | OPTION_BEGIN |
		      OPTION_TABLE_LOCK))
  {
    thd->options&= ~(ulong) (OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE);
    thd->server_status&= ~SERVER_STATUS_IN_TRANS;
    if (ha_commit(thd))
      error=1;
  }
  return error;
}


static HASH hash_user_connections;
extern  pthread_mutex_t LOCK_user_conn;

struct  user_conn {
  char *user;
  uint len, connections, questions, max;
  time_t intime;
};

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

#define DEF_USER_COUNT 50

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

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

static bool check_mqh(THD *thd, const char *user, const char *host,uint max)
{
  uint temp_len;
  char temp_user[USERNAME_LENGTH+HOSTNAME_LENGTH+2];
  struct  user_conn *uc;
  if (!user)
    user="";
  if (!host)
    host="";
  temp_len= (uint) (strxnmov(temp_user, sizeof(temp_user), user, "@", host,
			     NullS) - temp_user);
//This would be MUCH faster if there was already temp_user made in THD !!! May I ??
  (void) pthread_mutex_lock(&LOCK_user_conn);
  uc = (struct  user_conn *) hash_search(&hash_user_connections,
					 (byte*) temp_user, temp_len);
  if (uc) /* user found ; check for no. of queries */
  {
    bool my_start = thd->start_time != 0;
    time_t check_time = (my_start) ?  thd->start_time : time(NULL);
    if (check_time  - uc->intime >= 3600)
    {
      uc->questions=(uint)my_start;
      uc->intime=check_time;
    }
    else if (uc->max && ++(uc->questions) > uc->max)
    {
      (void) pthread_mutex_unlock(&LOCK_user_conn);
      send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);	// change this to appropriate message
      return 1;
    }
  }
  else
  {
    struct user_conn *uc= ((struct user_conn*)
			   my_malloc(sizeof(struct user_conn) + temp_len+1,
				     MYF(MY_WME)));
    if (!uc)
    {
      send_error(&current_thd->net, 0, NullS);	// Out of memory
      (void) pthread_mutex_unlock(&LOCK_user_conn);
      return 1;
    }      
    uc->user=(char*) (uc+1);
    memcpy(uc->user,temp_user,temp_len+1);
    uc->len = temp_len;
    uc->connections = 1; 
    uc->questions=0;
    uc->max=max;
    uc->intime=current_thd->thr_create_time;
    if (hash_insert(&hash_user_connections, (byte*) uc))
    {
      my_free((char*) uc,0);
      send_error(&current_thd->net, 0, NullS);	// Out of memory
      (void) pthread_mutex_unlock(&LOCK_user_conn);
      return 1;
    }
  }
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  return 0;
}

/*
** Check if user is ok
** Updates:
** thd->user, thd->master_access, thd->priv_user, thd->db, thd->db_access
*/

static bool check_user(THD *thd,enum_server_command command, const char *user,
		       const char *passwd, const char *db, bool check_count)
{
  NET *net= &thd->net;
  uint max=0;
  thd->db=0;
  thd->db_length=0;

  if (!(thd->user = my_strdup(user, MYF(0))))
  {
    send_error(net,ER_OUT_OF_RESOURCES);
    return 1;
  }
  thd->master_access=acl_getroot(thd, thd->host, thd->ip, thd->user,
				 passwd, thd->scramble, &thd->priv_user,
				 protocol_version == 9 ||
				 !(thd->client_capabilities &
				   CLIENT_LONG_PASSWORD),&max);
  DBUG_PRINT("info",
	     ("Capabilities: %d  packet_length: %d  Host: '%s'  User: '%s'  Using password: %s  Access: %u  db: '%s'",
	      thd->client_capabilities, thd->max_packet_length,
	      thd->host_or_ip, thd->priv_user,
	      passwd[0] ? "yes": "no",
	      thd->master_access, thd->db ? thd->db : "*none*"));
  if (thd->master_access & NO_ACCESS)
  {
    net_printf(net, ER_ACCESS_DENIED_ERROR,
	       thd->user,
	       thd->host_or_ip,
	       passwd[0] ? ER(ER_YES) : ER(ER_NO));
    mysql_log.write(thd,COM_CONNECT,ER(ER_ACCESS_DENIED_ERROR),
		    thd->user,
		    thd->host_or_ip,
		    passwd[0] ? ER(ER_YES) : ER(ER_NO));
    return(1);					// Error already given
  }
  if (check_count)
  {
    VOID(pthread_mutex_lock(&LOCK_thread_count));
    bool tmp=(thread_count - delayed_insert_threads >= max_connections &&
	      !(thd->master_access & PROCESS_ACL));
    VOID(pthread_mutex_unlock(&LOCK_thread_count));
    if (tmp)
    {						// Too many connections
      send_error(net, ER_CON_COUNT_ERROR);
      return(1);
    }
  }
  if (mqh_used && max && check_mqh(thd,user,thd->host,max))
    return -1;
  mysql_log.write(thd,command,
		  (thd->priv_user == thd->user ?
		   (char*) "%s@%s on %s" :
		   (char*) "%s@%s as anonymous on %s"),
		  user,
		  thd->host_or_ip,
		  db ? db : (char*) "");
  thd->db_access=0;
  if (max_user_connections &&
      check_for_max_user_connections(user, thd->host, max))
    return -1;
  if (db && db[0])
  {
    bool error=test(mysql_change_db(thd,db));
    if (error)
      decrease_user_connections(thd->user,thd->host);
    return error;
  }
  else
    send_ok(net);				// Ready to handle questions
  return 0;					// ok
}

/*
** check for maximum allowable user connections
** if mysql server is started with corresponding
** variable that is greater then 0
*/

void init_max_user_conn(void) 
{
  (void) hash_init(&hash_user_connections,DEF_USER_COUNT,0,0,
		   (hash_get_key) get_key_conn, (void (*)(void*)) free_user,
		   0);
}


static int check_for_max_user_connections(const char *user, const char *host, uint max) 
{
  int error=1;
  uint temp_len;
  char temp_user[USERNAME_LENGTH+HOSTNAME_LENGTH+2];
  struct  user_conn *uc;
  if (!user)
    user="";
  if (!host)
    host="";
  DBUG_ENTER("check_for_max_user_connections");
  DBUG_PRINT("enter",("user: '%s'  host: '%s'", user, host));

  temp_len= (uint) (strxnmov(temp_user, sizeof(temp_user), user, "@", host,
			     NullS) - temp_user);
  (void) pthread_mutex_lock(&LOCK_user_conn);
  uc = (struct  user_conn *) hash_search(&hash_user_connections,
					 (byte*) temp_user, temp_len);
  if (uc) /* user found ; check for no. of connections */
  {
    if (max_user_connections ==  (uint) uc->connections) 
    {
      net_printf(&(current_thd->net),ER_TOO_MANY_USER_CONNECTIONS, temp_user);
      goto end;
    }
    uc->connections++; 
  }
  else
  {
    /* the user is not found in the cache; Insert it */
    struct user_conn *uc= ((struct user_conn*)
			   my_malloc(sizeof(struct user_conn) + temp_len+1,
				     MYF(MY_WME)));
    if (!uc)
    {
      send_error(&current_thd->net, 0, NullS);	// Out of memory
      goto end;
    }      
    uc->user=(char*) (uc+1);
    memcpy(uc->user,temp_user,temp_len+1);
    uc->len = temp_len;
    uc->connections = 1; 
    uc->questions=0;
    uc->max=max;
    uc->intime=current_thd->thr_create_time;
    if (hash_insert(&hash_user_connections, (byte*) uc))
    {
      my_free((char*) uc,0);
      send_error(&current_thd->net, 0, NullS);	// Out of memory
      goto end;
    }
  }
  error=0;

end:
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  DBUG_RETURN(error);
}


static void decrease_user_connections(const char *user, const char *host)
{
  char temp_user[USERNAME_LENGTH+HOSTNAME_LENGTH+2];
  int temp_len;
  struct user_conn *uc;
  if (!max_user_connections)
    return;
  if (!user)
    user="";
  if (!host)
    host="";
  DBUG_ENTER("decrease_user_connections");
  DBUG_PRINT("enter",("user: '%s'  host: '%s'", user, host));

  temp_len= (uint) (strxnmov(temp_user, sizeof(temp_user), user, "@", host,
			     NullS) - temp_user);
  (void) pthread_mutex_lock(&LOCK_user_conn);

  uc = (struct  user_conn *) hash_search(&hash_user_connections,
					 (byte*) temp_user, temp_len);
  DBUG_ASSERT(uc != 0);			// We should always find the user
  if (!uc)
    goto end;				// Safety; Something went wrong
  if (! --uc->connections && !mqh_used)
  {
    /* Last connection for user; Delete it */
    (void) hash_delete(&hash_user_connections,(byte*) uc);
  }
end:
  (void) pthread_mutex_unlock(&LOCK_user_conn);
  DBUG_VOID_RETURN;
}


void free_max_user_conn(void)
{
  hash_free(&hash_user_connections);
}

/*
** check connnetion and get priviliges
** returns 0 on ok, -1 < if error is given > 0 on error.
*/


static int
check_connections(THD *thd)
{
  uint connect_errors=0;
  NET *net= &thd->net;
  /*
  ** store the connection details
  */
  DBUG_PRINT("info", (("check_connections called by thread %d"),
	     thd->thread_id));
  DBUG_PRINT("info",("New connection received on %s",
			vio_description(net->vio)));
  if (!thd->host)                           // If TCP/IP connection
  {
    char ip[30];

    if (vio_peer_addr(net->vio,ip))
      return (ER_BAD_HOST_ERROR);
    if (!(thd->ip = my_strdup(ip,MYF(0))))
      return (ER_OUT_OF_RESOURCES);
    thd->host_or_ip=thd->ip;
#if !defined(HAVE_SYS_UN_H) || defined(HAVE_mit_thread)
    /* Fast local hostname resolve for Win32 */
    if (!strcmp(thd->ip,"127.0.0.1"))
      thd->host=(char*) localhost;
    else
#endif
    if (!(specialflag & SPECIAL_NO_RESOLVE))
    {
      vio_in_addr(net->vio,&thd->remote.sin_addr);
      thd->host=ip_to_hostname(&thd->remote.sin_addr,&connect_errors);
      if (connect_errors > max_connect_errors)
	return(ER_HOST_IS_BLOCKED);
    }
    DBUG_PRINT("info",("Host: %s  ip: %s",
		       thd->host ? thd->host : "unknown host",
		       thd->ip ? thd->ip : "unknown ip"));
    if (acl_check_host(thd->host,thd->ip))
      return(ER_HOST_NOT_PRIVILEGED);
  }
  else /* Hostname given means that the connection was on a socket */
  {
    DBUG_PRINT("info",("Host: %s",thd->host));
    thd->host_or_ip=thd->host;
    thd->ip=0;
    bzero((char*) &thd->remote,sizeof(struct sockaddr));
  }
  vio_keepalive(net->vio, TRUE);

  ulong pkt_len=0;
  {
    /* buff[] needs to big enough to hold the server_version variable */
    char buff[SERVER_VERSION_LENGTH + SCRAMBLE_LENGTH+32],*end;
    int client_flags = CLIENT_LONG_FLAG | CLIENT_CONNECT_WITH_DB;

    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 avalaible! */
#endif /* HAVE_OPENSSL */

    end=strnmov(buff,server_version,SERVER_VERSION_LENGTH)+1;
    int4store((uchar*) end,thd->thread_id);
    end+=4;
    memcpy(end,thd->scramble,SCRAMBLE_LENGTH+1);
    end+=SCRAMBLE_LENGTH +1;
    int2store(end,client_flags);
    end[2]=(char) MY_CHARSET_CURRENT;
    int2store(end+3,thd->server_status);
    bzero(end+5,13);
    end+=18;
    if (net_write_command(net,(uchar) protocol_version, 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(net_buffer_length))
    return(ER_OUT_OF_RESOURCES);

  thd->client_capabilities=uint2korr(net->read_pos);
  if (thd->client_capabilities & CLIENT_IGNORE_SPACE)
    thd->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. */
    DBUG_PRINT("info", ("IO layer change in progress..."));
    sslaccept(ssl_acceptor_fd, net->vio, thd->inactive_timeout);
    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);
    }
  }
  else
  {
    DBUG_PRINT("info", ("Leaving IO layer intact"));
    if (pkt_len < NORMAL_HANDSHAKE_SIZE)
    {
      inc_host_errors(&thd->remote.sin_addr);
      return ER_HANDSHAKE_ERROR;
    }
  }
#endif

  thd->max_packet_length=uint3korr(net->read_pos+2);
  char *user=   (char*) net->read_pos+5;
  char *passwd= strend(user)+1;
  char *db=0;
  if (passwd[0] && strlen(passwd) != SCRAMBLE_LENGTH)
    return ER_HANDSHAKE_ERROR;
  if (thd->client_capabilities & CLIENT_CONNECT_WITH_DB)
    db=strend(passwd)+1;
  if (thd->client_capabilities & CLIENT_INTERACTIVE)
    thd->inactive_timeout=net_interactive_timeout;
  if ((thd->client_capabilities & CLIENT_TRANSACTIONS) &&
      opt_using_transactions)
    thd->net.return_status= &thd->server_status;
  net->timeout=(uint) net_read_timeout;
  if (check_user(thd,COM_CONNECT, user, passwd, db, 1))
    return (-1);
  thd->password=test(passwd[0]);
  return 0;
}


pthread_handler_decl(handle_one_connection,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__) && !defined(OS2)	/* Win32 calls this in pthread_create */
  if (my_thread_init()) // needed to be called first before we call
    // DBUG_ macros
  {
    close_connection(&thd->net,ER_OUT_OF_RESOURCES);
    statistic_increment(aborted_connects,&LOCK_thread_count);
    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();				// IRENA; testing ?
#elif !defined(OS2)
  sigset_t set;
  VOID(sigemptyset(&set));			// Get mask in use
  VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals));
#endif
  if (thd->store_globals())
  {
    close_connection(&thd->net,ER_OUT_OF_RESOURCES);
    statistic_increment(aborted_connects,&LOCK_thread_count);
    end_thread(thd,0);
    return 0;
  }

  do
  {
    int error;
    NET *net= &thd->net;

    thd->mysys_var=my_thread_var;
    thd->dbug_thread_id=my_thread_id();
    thd->thread_stack= (char*) &thd;

    if ((error=check_connections(thd)))
    {						// Wrong permissions
      if (error > 0)
	net_printf(net,error,thd->host_or_ip);
#ifdef __NT__
      if (vio_type(net->vio) == VIO_TYPE_NAMEDPIPE)
	sleep(1);				/* must wait after eof() */
#endif
      statistic_increment(aborted_connects,&LOCK_thread_count);
      goto end_thread;
    }

    if (thd->max_join_size == HA_POS_ERROR)
      thd->options |= OPTION_BIG_SELECTS;
    if (thd->client_capabilities & CLIENT_COMPRESS)
      net->compress=1;				// Use compression

    thd->proc_info=0;				// Remove 'login'
    thd->command=COM_SLEEP;
    thd->version=refresh_version;
    thd->set_time();
    init_sql_alloc(&thd->mem_root,8192,8192);
    while (!net->error && net->vio != 0 && !thd->killed)
    {
      if (do_command(thd))
	break;
    }
    free_root(&thd->mem_root,MYF(0));
    if (net->error && net->vio != 0)
    {
      if (!thd->killed && opt_warnings)
      sql_print_error(ER(ER_NEW_ABORTING_CONNECTION),
		      thd->thread_id,(thd->db ? thd->db : "unconnected"),
		      thd->user ? thd->user : "unauthenticated",
		      thd->host_or_ip,
		      (net->last_errno ? ER(net->last_errno) :
		       ER(ER_UNKNOWN_ERROR)));
      send_error(net,net->last_errno,NullS);
      thread_safe_increment(aborted_threads,&LOCK_thread_count);
    }

    decrease_user_connections(thd->user,thd->host);
end_thread:
    close_connection(net);
    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;
  } while (!(test_flags & TEST_NO_THREADS));
  /* The following is only executed if we are not using --one-thread */
  return(0);					/* purecov: deadcode */
}

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

pthread_handler_decl(handle_bootstrap,arg)
{
  THD *thd=(THD*) arg;
  FILE *file=bootstrap_file;
  char *buff;

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

  pthread_detach_this_thread();
  thd->thread_stack= (char*) &thd;
  thd->mysys_var=my_thread_var;
  thd->dbug_thread_id=my_thread_id();
#if !defined(__WIN__) && !defined(OS2)
  sigset_t set;
  VOID(sigemptyset(&set));			// Get mask in use
  VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals));
#endif

  if (thd->max_join_size == (ulong) ~0L)
    thd->options |= OPTION_BIG_SELECTS;

  thd->proc_info=0;
  thd->version=refresh_version;
  thd->priv_user=thd->user=(char*)"boot";

  buff= (char*) thd->net.buff;
  init_sql_alloc(&thd->mem_root,8192,8192);
  while (fgets(buff, thd->net.max_packet, file))
  {
    uint length=(uint) strlen(buff);
    while (length && (isspace(buff[length-1]) || buff[length-1] == ';'))
      length--;
    buff[length]=0;
    thd->current_tablenr=0;
    thd->query_length=length;
    thd->query= thd->memdup_w_gap(buff, length+1, thd->db_length+1);
    thd->query[length] = '\0';
    thd->query_id=query_id++;
    mysql_parse(thd,thd->query,length);
    close_thread_tables(thd);			// Free tables
    if (thd->fatal_error)
      break;
    free_root(&thd->mem_root,MYF(MY_KEEP_PREALLOC));
  }
  thd->priv_user=thd->user=0;

  /* thd->fatal_error should be set in case something went wrong */
end:
  (void) pthread_mutex_lock(&LOCK_thread_count);
  thread_count--;
  (void) pthread_cond_broadcast(&COND_thread_count);
  (void) pthread_mutex_unlock(&LOCK_thread_count);
  my_thread_end();
  pthread_exit(0);
  DBUG_RETURN(0);				// Never reached
}


inline void free_items(THD *thd)
{
    /* This works because items are allocated with sql_alloc() */
  for (Item *item=thd->free_list ; item ; item=item->next)
    delete item;
}

int mysql_table_dump(THD* thd, char* db, char* tbl_name, int fd)
{
  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->real_name = table_list->name = tbl_name;
  table_list->lock_type = TL_READ_NO_INSERT;
  table_list->next = 0;
  remove_escape(table_list->real_name);

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

  if (!db || check_db_name(db))
  {
    net_printf(&thd->net,ER_WRONG_DB_NAME, db ? db : "NULL");
    goto err;
  }
  if (check_access(thd, SELECT_ACL, db, &table_list->grant.privilege))
    goto err;
  if (grant_option && check_grant(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, -1)))
  {
    my_error(ER_GET_ERRNO, MYF(0));
    goto err;
  }
  net_flush(&thd->net);
  if ((error = table->file->dump(thd,fd)))
    my_error(ER_GET_ERRNO, MYF(0));

err:
  close_thread_tables(thd);
  DBUG_RETURN(error);
}


	/* Execute one command from socket (query or simple command) */

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;
  thd->current_tablenr=0;

  packet=0;
  old_timeout=net->timeout;
  net->timeout=(uint) thd->inactive_timeout;	// Wait max for 8 hours
  net->last_error[0]=0;				// Clear error message
  net->last_errno=0;

  net_new_transaction(net);
  if ((packet_length=my_net_read(net)) == packet_error)
  {
     DBUG_PRINT("info",("Got error reading command from socket %s",
			vio_description(net->vio) ));
    return TRUE;
  }
  else
  {
    packet=(char*) net->read_pos;
    command = (enum enum_server_command) (uchar) packet[0];
    DBUG_PRINT("info",("Command on %s = %d (%s)",
		       vio_description(net->vio), command,
		       command_name[command]));
  }
  net->timeout=old_timeout;			// Timeout for writing
  DBUG_RETURN(dispatch_command(command,thd, packet+1, (uint) packet_length));
}


bool dispatch_command(enum enum_server_command command, THD *thd,
		      char* packet, uint packet_length)
{
  NET *net= &thd->net;
  bool	error=0;
  // commands which will always take a long time should be marked with
  // this so that they will not get logged to the slow query log
  bool slow_command=FALSE;
  DBUG_ENTER("dispatch_command");

  thd->command=command;
  VOID(pthread_mutex_lock(&LOCK_thread_count));
  thd->query_id=query_id;
  if (command != COM_STATISTICS && command != COM_PING)
    query_id++;
  thread_running++;
  VOID(pthread_mutex_unlock(&LOCK_thread_count));
  thd->set_time();
  thd->lex.select_lex.options=0;		// We store status here
  switch (command) {
  case COM_INIT_DB:
    thread_safe_increment(com_stat[SQLCOM_CHANGE_DB],&LOCK_thread_count);
    if (!mysql_change_db(thd,packet))
      mysql_log.write(thd,command,"%s",thd->db);
    break;
  case COM_REGISTER_SLAVE:
  {
    if (register_slave(thd, (uchar*)packet, packet_length))
      send_error(&thd->net);
    else
      send_ok(&thd->net);
    break;
  }
  case COM_TABLE_DUMP:
    {
      thread_safe_increment(com_other,&LOCK_thread_count);
      slow_command = TRUE;
      uint db_len = *(uchar*)packet;
      uint tbl_len = *(uchar*)(packet + db_len + 1);
      char* db = thd->alloc(db_len + tbl_len + 2);
      memcpy(db, packet + 1, db_len);
      char* tbl_name = db + db_len;
      *tbl_name++ = 0;
      memcpy(tbl_name, packet + db_len + 2, tbl_len);
      tbl_name[tbl_len] = 0;
      if (mysql_table_dump(thd, db, tbl_name, -1))
	send_error(&thd->net); // dump to NET

      break;
    }
  case COM_CHANGE_USER:
  {
    thread_safe_increment(com_other,&LOCK_thread_count);
    char *user=   (char*) packet;
    char *passwd= strend(user)+1;
    char *db=     strend(passwd)+1;

    /* Save user and privileges */
    uint save_master_access=thd->master_access;
    uint save_db_access=    thd->db_access;
    uint save_db_length=    thd->db_length;
    char *save_user=	    thd->user;
    char *save_priv_user=   thd->priv_user;
    char *save_db=	    thd->db;

    if ((uint) ((uchar*) db - net->read_pos) > packet_length)
    {						// Check if protocol is ok
      send_error(net, ER_UNKNOWN_COM_ERROR);
      break;
    }
    if (check_user(thd, COM_CHANGE_USER, user, passwd, db, 0))
    {						// Restore old user
      x_free(thd->user);
      x_free(thd->db);
      thd->master_access=save_master_access;
      thd->db_access=save_db_access;
      thd->db=save_db;
      thd->db_length=save_db_length;
      thd->user=save_user;
      thd->priv_user=save_priv_user;
      break;
    }
    decrease_user_connections (save_user, thd->host);
    x_free((gptr) save_db);
    x_free((gptr) save_user);
    thd->password=test(passwd[0]);
    break;
  }

  case COM_QUERY:
  {
    packet_length--;				// Remove end null
    /* Remove garage at start and end of query */
    while (isspace(packet[0]) && packet_length > 0)
    {
      packet++;
      packet_length--;
    }
    char *pos=packet+packet_length;		// Point at end null
    while (packet_length > 0 && (pos[-1] == ';' || isspace(pos[-1])))
    {
      pos--;
      packet_length--;
    }
    /* We must allocate some extra memory for query cache */
    if (!(thd->query= (char*) thd->memdup_w_gap((gptr) (packet),
						packet_length,
						thd->db_length+2)))
      break;
    thd->query[packet_length]=0;
    thd->packet.shrink(net_buffer_length);	// Reclaim some memory
    if (!(specialflag & SPECIAL_NO_PRIOR))
      my_pthread_setprio(pthread_self(),QUERY_PRIOR);
    mysql_log.write(thd,command,"%s",thd->query);
    DBUG_PRINT("query",("%s",thd->query));
    if (mqh_used && check_mqh(thd,thd->user,thd->host,0))
    {
      error = TRUE;
      net->error = 0;
      break;
    }
    /* thd->query_length is set by mysql_parse() */
    mysql_parse(thd,thd->query,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
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);	/* purecov: inspected */
    break;
#else
  {
    char *fields;
    TABLE_LIST table_list;
    thread_safe_increment(com_stat[SQLCOM_SHOW_FIELDS],&LOCK_thread_count);
    bzero((char*) &table_list,sizeof(table_list));
    if (!(table_list.db=thd->db))
    {
      send_error(net,ER_NO_DB_ERROR);
      break;
    }
    thd->free_list=0;
    table_list.name=table_list.real_name=thd->strdup(packet);
    packet=strend(packet)+1;
    // command not cachable => no gap for data base name
    if (!(thd->query=fields=thd->memdup(packet,thd->query_length+1)))
      break;
    mysql_log.write(thd,command,"%s %s",table_list.real_name,fields);
    remove_escape(table_list.real_name);	// This can't have wildcards

    if (check_access(thd,SELECT_ACL,table_list.db,&thd->col_access))
      break;
    table_list.grant.privilege=thd->col_access;
    if (grant_option && check_grant(thd,SELECT_ACL,&table_list,2))
      break;
    mysqld_list_fields(thd,&table_list,fields);
    free_items(thd);
    break;
  }
#endif
  case COM_QUIT:
    /* We don't calculate statistics for this command */
    mysql_log.write(thd,command,NullS);
    net->error=0;				// Don't give 'abort' message
    error=TRUE;					// End server
    break;

  case COM_CREATE_DB:				// QQ: To be removed
    {
      thread_safe_increment(com_stat[SQLCOM_CREATE_DB],&LOCK_thread_count);
      char *db=thd->strdup(packet);
      // null test to handle EOM
      if (!db || !stripp_sp(db) || check_db_name(db))
      {
	net_printf(&thd->net,ER_WRONG_DB_NAME, db ? db : "NULL");
	break;
      }
      if (check_access(thd,CREATE_ACL,db,0,1))
	break;
      mysql_log.write(thd,command,packet);
      mysql_create_db(thd,db,0,0);
      break;
    }
  case COM_DROP_DB:				// QQ: To be removed
    {
      thread_safe_increment(com_stat[SQLCOM_DROP_DB],&LOCK_thread_count);
      char *db=thd->strdup(packet);
      // null test to handle EOM
      if (!db || !stripp_sp(db) || check_db_name(db))
      {
	net_printf(&thd->net,ER_WRONG_DB_NAME, db ? db : "NULL");
	break;
      }
      if (thd->locked_tables || thd->active_transaction())
      {
	send_error(&thd->net,ER_LOCK_OR_ACTIVE_TRANSACTION);
	break;
      }
      mysql_log.write(thd,command,db);
      mysql_rm_db(thd,db,0,0);
      break;
    }
  case COM_BINLOG_DUMP:
    {
      thread_safe_increment(com_other,&LOCK_thread_count);
      slow_command = TRUE;
      if (check_access(thd, FILE_ACL, any_db))
	break;
      mysql_log.write(thd,command, 0);

      ulong pos;
      ushort flags;
      uint32 slave_server_id;
      pos = uint4korr(packet);
      flags = uint2korr(packet + 4);
      pthread_mutex_lock(&LOCK_server_id);
      thd->server_id=0; /* avoid suicide */
      kill_zombie_dump_threads(slave_server_id = uint4korr(packet+6));
      thd->server_id = slave_server_id;
      pthread_mutex_unlock(&LOCK_server_id);
      mysql_binlog_send(thd, thd->strdup(packet + 10), 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;
    }
  case COM_REFRESH:
    {
      thread_safe_increment(com_stat[SQLCOM_FLUSH],&LOCK_thread_count);
      ulong options= (ulong) (uchar) packet[0];
      if (check_access(thd,RELOAD_ACL,any_db))
	break;
      mysql_log.write(thd,command,NullS);
      if (reload_acl_and_cache(thd, options, (TABLE_LIST*) 0))
	send_error(net,0);
      else
	send_eof(net);
      if (mqh_used && hash_user_connections.array.buffer == 0)
	init_max_user_conn();
      break;
    }
  case COM_SHUTDOWN:
    thread_safe_increment(com_other,&LOCK_thread_count);
    if (check_access(thd,SHUTDOWN_ACL,any_db))
      break; /* purecov: inspected */
    DBUG_PRINT("quit",("Got shutdown command"));
    mysql_log.write(thd,command,NullS);
    send_eof(net);
#ifdef __WIN__
    sleep(1);					// must wait after eof()
#endif
#ifndef OS2
    send_eof(net);				// This is for 'quit request'
#endif
    close_connection(net);
    close_thread_tables(thd);			// Free before kill
    free_root(&thd->mem_root,MYF(0));
    kill_mysql();
    error=TRUE;
    break;

  case COM_STATISTICS:
  {
    mysql_log.write(thd,command,NullS);
    thread_safe_increment(com_stat[SQLCOM_SHOW_STATUS],&LOCK_thread_count);
    char buff[200];
    ulong uptime = (ulong) (thd->start_time - start_time);
    sprintf((char*) buff,
	    "Uptime: %ld  Threads: %d  Questions: %lu  Slow queries: %ld  Opens: %ld  Flush tables: %ld  Open tables: %u  Queries per second avg: %.3f",
	    uptime,
	    (int) thread_count,thd->query_id,long_query_count,
	    opened_tables,refresh_version, cached_tables(),
	    uptime ? (float)thd->query_id/(float)uptime : 0);
#ifdef SAFEMALLOC
    if (lCurMemory)				// Using SAFEMALLOC
      sprintf(strend(buff), "  Memory in use: %ldK  Max memory used: %ldK",
	      (lCurMemory+1023L)/1024L,(lMaxMemory+1023L)/1024L);
 #endif
    VOID(my_net_write(net, buff,(uint) strlen(buff)));
    VOID(net_flush(net));
    break;
  }
  case COM_PING:
    thread_safe_increment(com_other,&LOCK_thread_count);
    send_ok(net);				// Tell client we are alive
    break;
  case COM_PROCESS_INFO:
    thread_safe_increment(com_stat[SQLCOM_SHOW_PROCESSLIST],&LOCK_thread_count);
    if (!thd->priv_user[0] && check_process_priv(thd))
      break;
    mysql_log.write(thd,command,NullS);
    mysqld_list_processes(thd,thd->master_access & PROCESS_ACL ? NullS :
			  thd->priv_user,0);
    break;
  case COM_PROCESS_KILL:
  {
    thread_safe_increment(com_stat[SQLCOM_KILL],&LOCK_thread_count);
    ulong id=(ulong) uint4korr(packet);
    kill_one_thread(thd,id);
    break;
  }
  case COM_DEBUG:
    thread_safe_increment(com_other,&LOCK_thread_count);
    if (check_process_priv(thd))
      break;					/* purecov: inspected */
    mysql_print_status(thd);
    mysql_log.write(thd,command,NullS);
    send_eof(net);
    break;
  case COM_SLEEP:
  case COM_CONNECT:				// Impossible here
  case COM_TIME:				// Impossible from client
  case COM_DELAYED_INSERT:
  default:
    send_error(net, ER_UNKNOWN_COM_ERROR);
    break;
  }
  if (thd->lock || thd->open_tables)
  {
    thd->proc_info="closing tables";
    close_thread_tables(thd);			/* Free tables */
  }

  if (thd->fatal_error)
    send_error(net,0);				// End of memory ?

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

  /* If not reading from backup and if the query took too long */
  if (!slow_command && !thd->user_time) // do not log 'slow_command' queries
  {
    thd->proc_info="logging slow query";

    if ((ulong) (thd->start_time - thd->time_after_lock) > long_query_time ||
	((thd->lex.select_lex.options &
	  (QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED)) &&
	 (specialflag & SPECIAL_LONG_LOG_FORMAT)))
    {
      long_query_count++;
      mysql_slow_log.write(thd, thd->query, thd->query_length, start_of_query);
    }
  }
  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;
  thread_running--;
  VOID(pthread_mutex_unlock(&LOCK_thread_count));
  thd->packet.shrink(net_buffer_length);	// Reclaim some memory
  free_root(&thd->mem_root,MYF(MY_KEEP_PREALLOC));
  DBUG_RETURN(error);
}

/****************************************************************************
** mysql_execute_command
** Execute command saved in thd and current_lex->sql_command
****************************************************************************/

void
mysql_execute_command(void)
{
  int	res=0;
  THD	*thd=current_thd;
  LEX	*lex= &thd->lex;
  TABLE_LIST *tables=(TABLE_LIST*) lex->select_lex.table_list.first;
  SELECT_LEX *select_lex = lex->select;
  DBUG_ENTER("mysql_execute_command");

  if (thd->slave_thread)
  {
    /* 
      Skip if we are in the slave thread, some table rules have been
      given and the table list says the query should not be replicated
    */
    if (table_rules_on && tables && !tables_ok(thd,tables))
      DBUG_VOID_RETURN;
#ifndef TO_BE_DELETED
    /*
       This is a workaround to deal with the shortcoming in 3.23.44-3.23.46
       masters in RELEASE_LOCK() logging. We re-write SELECT RELEASE_LOCK()
       as DO RELEASE_LOCK()
    */
    if (lex->sql_command == SQLCOM_SELECT)
    {
      lex->sql_command = SQLCOM_DO;
      lex->insert_list = &select_lex->item_list;
    }
#endif
  }
  
  /*
    Skip if we are in the slave thread, some table rules have been given
    and the table list says the query should not be replicated
  */
  if ((lex->select_lex.next && create_total_list(thd,lex,&tables)) ||
      (table_rules_on && tables && thd->slave_thread &&
       !tables_ok(thd,tables)))
    DBUG_VOID_RETURN;
  if (lex->sql_command==SQLCOM_UPDATE &&  select_lex->table_list.elements > 1)
    lex->sql_command=SQLCOM_MULTI_UPDATE; 

  thread_safe_increment(com_stat[lex->sql_command],&LOCK_thread_count);
  switch (lex->sql_command) {
  case SQLCOM_SELECT:
  {
    select_result *result;
    if (select_lex->options & SELECT_DESCRIBE)
      lex->exchange=0;
    if (tables)
    {
      res=check_table_access(thd,
			     lex->exchange ? SELECT_ACL | FILE_ACL :
			     SELECT_ACL,
			     tables);
    }
    else
      res=check_access(thd, lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL,
		       any_db);
    if (res)
    {
      res=0;
      break;					// Error message is given
    }

    thd->offset_limit=select_lex->offset_limit;
    thd->select_limit=select_lex->select_limit+select_lex->offset_limit;
    if (thd->select_limit < select_lex->select_limit)
      thd->select_limit= HA_POS_ERROR;		// no limit
    if (thd->select_limit == HA_POS_ERROR)
      select_lex->options&= ~OPTION_FOUND_ROWS;

    if (lex->exchange)
    {
      if (lex->exchange->dumpfile)
      {
	if (!(result=new select_dump(lex->exchange)))
	{
	  res= -1;
	  break;
	}
      }
      else
      {
	if (!(result=new select_export(lex->exchange)))
	{
	  res= -1;
	  break;
	}
      }
    }
    else if (!(result=new select_send()))
    {
      res= -1;
#ifdef DELETE_ITEMS
      delete select_lex->having;
      delete select_lex->where;
#endif
      break;
    }
    else
    {
      /*
	Normal select:
	Change lock if we are using SELECT HIGH PRIORITY,
	FOR UPDATE or IN SHARE MODE
      */
      TABLE_LIST *table;
      for (table = tables ; table ; table=table->next)
	table->lock_type= lex->lock_option;
    }

    if (!(res=open_and_lock_tables(thd,tables)))
    {
      query_cache.store_query(thd, tables);
      res=handle_select(thd, lex, result);
    }
    else
      delete result;
    break;
  }
  case SQLCOM_DO:
    res=mysql_do(thd, *lex->insert_list);
    break;

  case SQLCOM_PURGE:
  {
    if (check_process_priv(thd))
      goto error;
    res = purge_master_logs(thd, lex->to_log);
    break;
  }
  case SQLCOM_SHOW_NEW_MASTER:
  {
    if (check_access(thd, FILE_ACL, any_db))
      goto error;
    res = show_new_master(thd);
    break;
  }
  case SQLCOM_SHOW_SLAVE_HOSTS:
  {
    if (check_access(thd, FILE_ACL, any_db))
      goto error;
    res = show_slave_hosts(thd);
    break;
  }
  case SQLCOM_SHOW_BINLOG_EVENTS:
  {
    if (check_access(thd, FILE_ACL, any_db))
      goto error;
    res = show_binlog_events(thd);
    break;
  }
  case SQLCOM_BACKUP_TABLE:
  {
    if (check_db_used(thd,tables) ||
	check_table_access(thd,SELECT_ACL, tables) ||
	check_access(thd, FILE_ACL, any_db))
      goto error; /* purecov: inspected */
    res = mysql_backup_table(thd, tables);

    break;
  }
  case SQLCOM_RESTORE_TABLE:
  {
    if (check_db_used(thd,tables) ||
	check_table_access(thd,INSERT_ACL, tables) ||
	check_access(thd, FILE_ACL, any_db))
      goto error; /* purecov: inspected */
    res = mysql_restore_table(thd, tables);
    break;
  }
  case SQLCOM_CHANGE_MASTER:
  {
    if (check_access(thd, PROCESS_ACL, any_db))
      goto error;
    res = change_master(thd);
    break;
  }
  case SQLCOM_SHOW_SLAVE_STAT:
  {
    if (check_process_priv(thd))
      goto error;
    res = show_master_info(thd);
    break;
  }
  case SQLCOM_SHOW_MASTER_STAT:
  {
    if (check_process_priv(thd))
      goto error;
    res = show_binlog_info(thd);
    break;
  }

  case SQLCOM_LOAD_MASTER_DATA: // sync with master
    if (check_process_priv(thd))
      goto error;
    res = load_master_data(thd);
    break;

  case SQLCOM_LOAD_MASTER_TABLE:

    if (!tables->db)
      tables->db=thd->db;
    if (check_access(thd,CREATE_ACL,tables->db,&tables->grant.privilege))
      goto error;				/* purecov: inspected */
    if (grant_option)
    {
      /* Check that the first table has CREATE privilege */
      TABLE_LIST *tmp_table_list=tables->next;
      tables->next=0;
      bool error=check_grant(thd,CREATE_ACL,tables);
      tables->next=tmp_table_list;
      if (error)
	goto error;
    }
    if (strlen(tables->name) > NAME_LEN)
    {
      net_printf(&thd->net,ER_WRONG_TABLE_NAME,tables->name);
      break;
    }

    if (fetch_nx_table(thd, tables->db, tables->real_name, &glob_mi, 0))
      break;      // fetch_nx_table did send the error to the client
    send_ok(&thd->net);
    break;

  case SQLCOM_CREATE_TABLE:
    if (!tables->db)
      tables->db=thd->db;
    if (check_access(thd,CREATE_ACL,tables->db,&tables->grant.privilege) ||
	check_merge_table_access(thd, tables->db,
				 (TABLE_LIST *)
				 lex->create_info.merge_list.first))
      goto error;				/* purecov: inspected */
    if (grant_option)
    {
      /* Check that the first table has CREATE privilege */
      TABLE_LIST *tmp_table_list=tables->next;
      tables->next=0;
      bool error=check_grant(thd,CREATE_ACL,tables);
      tables->next=tmp_table_list;
      if (error)
	goto error;
    }
    if (strlen(tables->name) > NAME_LEN)
    {
      net_printf(&thd->net,ER_WRONG_TABLE_NAME,tables->name);
      res=0;
      break;
    }
#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,
			   tables->name) ||
	append_file_to_dir(thd,&lex->create_info.index_file_name,
			   tables->name))
    {
      res=-1;
      break;
    }
#endif
    if (select_lex->item_list.elements)		// With select
    {
      select_result *result;

      if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE) &&
	  check_dup(tables->db, tables->real_name, tables->next))
      {
	net_printf(&thd->net,ER_INSERT_TABLE_USED,tables->real_name);
	DBUG_VOID_RETURN;
      }
      if (tables->next)
      {
	TABLE_LIST *table;
	if (check_table_access(thd, SELECT_ACL, tables->next))
	  goto error;				// Error message is given
	for (table = tables->next ; table ; table=table->next)
	  table->lock_type= lex->lock_option;
      }
      thd->offset_limit=select_lex->offset_limit;
      thd->select_limit=select_lex->select_limit+select_lex->offset_limit;
      if (thd->select_limit < select_lex->select_limit)
	thd->select_limit= HA_POS_ERROR;		// No limit

      /* Skip first table, which is the table we are creating */
      lex->select_lex.table_list.first=
	(byte*) (((TABLE_LIST *) lex->select_lex.table_list.first)->next);
      if (!(res=open_and_lock_tables(thd,tables->next)))
      {
        if ((result=new select_create(tables->db ? tables->db : thd->db,
                                      tables->real_name, &lex->create_info,
                                      lex->create_list,
                                      lex->key_list,
                                      select_lex->item_list,lex->duplicates)))
          res=handle_select(thd, lex, result);
	else
	  res= -1;
      }
    }
    else // regular create
    {
      res = mysql_create_table(thd,tables->db ? tables->db : thd->db,
			       tables->real_name, &lex->create_info,
			       lex->create_list,
			       lex->key_list,0, 0); // do logging
      if (!res)
	send_ok(&thd->net);
    }
    break;
  case SQLCOM_CREATE_INDEX:
    if (!tables->db)
      tables->db=thd->db;
    if (check_access(thd,INDEX_ACL,tables->db,&tables->grant.privilege))
      goto error; /* purecov: inspected */
    if (grant_option && check_grant(thd,INDEX_ACL,tables))
      goto error;
    if (end_active_trans(thd))
      res= -1;
    else
      res = mysql_create_index(thd, tables, lex->key_list);
    break;

  case SQLCOM_SLAVE_START:
    start_slave(thd);
    break;
  case SQLCOM_SLAVE_STOP:
    stop_slave(thd);
    break;

  case SQLCOM_ALTER_TABLE:
#if defined(DONT_ALLOW_SHOW_COMMANDS)
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND); /* purecov: inspected */
    break;
#else
    {
      uint priv=0;
      if (lex->name && strlen(lex->name) > NAME_LEN)
      {
	net_printf(&thd->net,ER_WRONG_TABLE_NAME,lex->name);
	res=0;
	break;
      }
      if (!tables->db)
	tables->db=thd->db;
      if (!select_lex->db)
	select_lex->db=tables->db;
      if (check_access(thd,ALTER_ACL,tables->db,&tables->grant.privilege) ||
	  check_access(thd,INSERT_ACL | CREATE_ACL,select_lex->db,&priv) ||
	  check_merge_table_access(thd, tables->db, 
				   (TABLE_LIST *)
				   lex->create_info.merge_list.first))
	goto error;				/* purecov: inspected */
      if (!tables->db)
	tables->db=thd->db;
      if (grant_option)
      {
	if (check_grant(thd,ALTER_ACL,tables))
	  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.real_name=lex->name;
	  tmp_table.db=select_lex->db;
	  tmp_table.grant.privilege=priv;
	  if (check_grant(thd,INSERT_ACL | CREATE_ACL,tables))
	    goto error;
	}
      }
      /* Don't yet allow changing of symlinks with ALTER TABLE */
      lex->create_info.data_file_name=lex->create_info.index_file_name=0;
      /* ALTER TABLE ends previous transaction */
      if (end_active_trans(thd))
	res= -1;
      else
      {
	res= mysql_alter_table(thd, select_lex->db, lex->name,
			       &lex->create_info,
			       tables, lex->create_list,
			       lex->key_list, lex->drop_list, lex->alter_list,
                               (ORDER *) select_lex->order_list.first,
			       lex->drop_primary, lex->duplicates,
			       lex->alter_keys_onoff, lex->simple_alter);
      }
      break;
    }
#endif
  case SQLCOM_RENAME_TABLE:
  {
    TABLE_LIST *table;
    if (check_db_used(thd,tables))
      goto error;
    for (table=tables ; table ; table=table->next->next)
    {
      if (check_access(thd, ALTER_ACL | DROP_ACL, table->db,
		       &table->grant.privilege) ||
	  check_access(thd, INSERT_ACL | CREATE_ACL, table->next->db,
		       &table->next->grant.privilege))
	goto error;
      if (grant_option)
      {
	TABLE_LIST old_list,new_list;
	old_list=table[0];
	new_list=table->next[0];
	old_list.next=new_list.next=0;
	if (check_grant(thd,ALTER_ACL,&old_list) ||
	    (!test_all_bits(table->next->grant.privilege,
			    INSERT_ACL | CREATE_ACL) &&
	     check_grant(thd,INSERT_ACL | CREATE_ACL, &new_list)))
	  goto error;
      }
    }
    query_cache.invalidate(tables);
    if (end_active_trans(thd))
      res= -1;
    else if (mysql_rename_tables(thd,tables))
      res= -1;
    break;
  }
  case SQLCOM_SHOW_BINLOGS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND); /* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    {
      if (check_process_priv(thd))
	goto error;
      res = show_binlogs(thd);
      break;
    }
#endif    
  case SQLCOM_SHOW_CREATE:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND); /* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    {
      if (check_db_used(thd, tables) ||
	  check_access(thd, SELECT_ACL | EXTRA_ACL, tables->db,
		       &tables->grant.privilege))
	goto error;
      res = mysqld_show_create(thd, tables);
      break;
    }
#endif
  case SQLCOM_REPAIR:
  {
    if (check_db_used(thd,tables) ||
	check_table_access(thd,SELECT_ACL | INSERT_ACL, tables))
      goto error; /* purecov: inspected */
    res = mysql_repair_table(thd, tables, &lex->check_opt);
    query_cache.invalidate(tables);
    break;
  }
  case SQLCOM_CHECK:
  {
    if (check_db_used(thd,tables) ||
	check_table_access(thd, SELECT_ACL | EXTRA_ACL , tables))
      goto error; /* purecov: inspected */
    res = mysql_check_table(thd, tables, &lex->check_opt);
    query_cache.invalidate(tables);
    break;
  }
  case SQLCOM_ANALYZE:
  {
    if (check_db_used(thd,tables) ||
	check_table_access(thd,SELECT_ACL | INSERT_ACL, tables))
      goto error; /* purecov: inspected */
    res = mysql_analyze_table(thd, tables, &lex->check_opt);
    break;
  }

  case SQLCOM_OPTIMIZE:
  {
    HA_CREATE_INFO create_info;
    if (check_db_used(thd,tables) ||
	check_table_access(thd,SELECT_ACL | INSERT_ACL, tables))
      goto error; /* purecov: inspected */
    if (specialflag & (SPECIAL_SAFE_MODE | SPECIAL_NO_NEW_FUNC))
    {
      /* Use ALTER TABLE */
      lex->create_list.empty();
      lex->key_list.empty();
      lex->col_list.empty();
      lex->drop_list.empty();
      lex->alter_list.empty();
      bzero((char*) &create_info,sizeof(create_info));
      create_info.db_type=DB_TYPE_DEFAULT;
      create_info.row_type=ROW_TYPE_DEFAULT;
      res= mysql_alter_table(thd, NullS, NullS, &create_info,
			     tables, lex->create_list,
			     lex->key_list, lex->drop_list, lex->alter_list,
                             (ORDER *) 0,
			     0,DUP_ERROR);
    }
    else
      res = mysql_optimize_table(thd, tables, &lex->check_opt);
    break;
  }
  case SQLCOM_UPDATE:
    if (check_access(thd,UPDATE_ACL,tables->db,&tables->grant.privilege))
      goto error;
    if (grant_option && check_grant(thd,UPDATE_ACL,tables))
      goto error;
    if (select_lex->item_list.elements != lex->value_list.elements)
    {
      send_error(&thd->net,ER_WRONG_VALUE_COUNT);
      DBUG_VOID_RETURN;
    }
    res = mysql_update(thd,tables,
		       select_lex->item_list,
		       lex->value_list,
		       select_lex->where,
                       (ORDER *) select_lex->order_list.first,
		       select_lex->select_limit,
		       lex->duplicates,
		       lex->lock_option);

#ifdef DELETE_ITEMS
    delete select_lex->where;
#endif
    break;
  case SQLCOM_INSERT:
    if (check_access(thd,INSERT_ACL,tables->db,&tables->grant.privilege))
      goto error; /* purecov: inspected */
    if (grant_option && check_grant(thd,INSERT_ACL,tables))
      goto error;
    res = mysql_insert(thd,tables,lex->field_list,lex->many_values,
		       lex->duplicates,
		       lex->lock_option);
    break;
  case SQLCOM_REPLACE:
    if (check_access(thd,INSERT_ACL | UPDATE_ACL | DELETE_ACL,
		     tables->db,&tables->grant.privilege))
      goto error; /* purecov: inspected */
    if (grant_option && check_grant(thd,INSERT_ACL | UPDATE_ACL | DELETE_ACL,
				    tables))

      goto error;
    res = mysql_insert(thd,tables,lex->field_list,lex->many_values,
		       DUP_REPLACE,
		       lex->lock_option);
    break;
  case SQLCOM_REPLACE_SELECT:
  case SQLCOM_INSERT_SELECT:
  {

    // Check that we have modify privileges for the first table and
    // select privileges for the rest
    {
      uint privilege= (lex->sql_command == SQLCOM_INSERT_SELECT ?
		       INSERT_ACL : INSERT_ACL | UPDATE_ACL | DELETE_ACL);
      TABLE_LIST *save_next=tables->next;
      tables->next=0;
      if (check_access(thd, privilege,
		       tables->db,&tables->grant.privilege) ||
	  (grant_option && check_grant(thd, privilege, tables)))
	goto error;
      tables->next=save_next;
      if ((res=check_table_access(thd, SELECT_ACL, save_next)))
	goto error;
    }

    select_result *result;
    thd->offset_limit=select_lex->offset_limit;
    thd->select_limit=select_lex->select_limit+select_lex->offset_limit;
    if (thd->select_limit < select_lex->select_limit)
      thd->select_limit= HA_POS_ERROR;		// No limit

    if (check_dup(tables->db, tables->real_name, tables->next))
    {
      net_printf(&thd->net,ER_INSERT_TABLE_USED,tables->real_name);
      DBUG_VOID_RETURN;
    }
    tables->lock_type=TL_WRITE;		// update first table
    {
      TABLE_LIST *table;
      for (table = tables->next ; table ; table=table->next)
	table->lock_type= lex->lock_option;
    }

    /* Skip first table, which is the table we are inserting in */
    lex->select_lex.table_list.first=
      (byte*) (((TABLE_LIST *) lex->select_lex.table_list.first)->next);
    if (!(res=open_and_lock_tables(thd, tables)))
    {
      if ((result=new select_insert(tables->table,&lex->field_list,
				    lex->duplicates)))
	res=handle_select(thd,lex,result);
    }
    else
      res= -1;
    break;
  }
  case SQLCOM_TRUNCATE:
    if (check_access(thd,DELETE_ACL,tables->db,&tables->grant.privilege))
      goto error; /* purecov: inspected */
    /*
      Don't allow this within a transaction because we want to use
      re-generate table
    */
    if (thd->locked_tables || thd->active_transaction())
    {
      send_error(&thd->net,ER_LOCK_OR_ACTIVE_TRANSACTION,NullS);
      goto error;
    }
    res=mysql_truncate(thd,tables);
    break;
  case SQLCOM_DELETE:
  {
    if (check_access(thd,DELETE_ACL,tables->db,&tables->grant.privilege))
      goto error; /* purecov: inspected */
    if (grant_option && check_grant(thd,DELETE_ACL,tables))
      goto error;
    // Set privilege for the WHERE clause
    tables->grant.want_privilege=(SELECT_ACL & ~tables->grant.privilege);
    /* TRUNCATE ends previous transaction */
    if (lex->sql_command == SQLCOM_TRUNCATE && end_active_trans(thd))
      res= -1;
    else
      res = mysql_delete(thd,tables, select_lex->where,
			 (ORDER*) select_lex->order_list.first,
                         select_lex->select_limit, lex->lock_option,
			 select_lex->options);
    break;
  }
  case SQLCOM_DELETE_MULTI:
  {
    TABLE_LIST *aux_tables=(TABLE_LIST *)thd->lex.auxilliary_table_list.first;
    TABLE_LIST *auxi;
    uint table_count=0;
    multi_delete *result;

    /* sql_yacc guarantees that tables and aux_tables are not zero */
    if (check_db_used(thd, tables) || check_db_used(thd,aux_tables) ||
	check_table_access(thd,SELECT_ACL, tables) || 
	check_table_access(thd,DELETE_ACL, aux_tables))
      goto error;
    if ((thd->options & OPTION_SAFE_UPDATES) && !select_lex->where)
    {		
      send_error(&thd->net,ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE);
      goto error;
    }
    for (auxi=(TABLE_LIST*) aux_tables ; auxi ; auxi=auxi->next)
    {
      table_count++;
      /* All tables in aux_tables must be found in FROM PART */
      TABLE_LIST *walk;
      for (walk=(TABLE_LIST*) tables ; walk ; walk=walk->next)
      {
	if (!strcmp(auxi->real_name,walk->real_name) &&
	    !strcmp(walk->db,auxi->db))
	  break;
      }
      if (!walk)
      {
	net_printf(&thd->net,ER_NONUNIQ_TABLE,auxi->real_name);
	goto error;
      }
      auxi->lock_type=walk->lock_type=TL_WRITE;
      auxi->table= (TABLE *) walk;		// Remember corresponding table
    }
    tables->grant.want_privilege=(SELECT_ACL & ~tables->grant.privilege);
    if (add_item_to_list(new Item_null()))
    {
      res= -1;
      break;
    }
    thd->proc_info="init";
    if ((res=open_and_lock_tables(thd,tables)))
      break;
    /* Fix tables-to-be-deleted-from list to point at opened tables */
    for (auxi=(TABLE_LIST*) aux_tables ; auxi ; auxi=auxi->next)
      auxi->table= ((TABLE_LIST*) auxi->table)->table;
    if ((result=new multi_delete(thd,aux_tables,lex->lock_option,
				 table_count)) && ! thd->fatal_error)
    {
      res=mysql_select(thd,tables,select_lex->item_list,
		       select_lex->where,
		       (ORDER *)NULL,(ORDER *)NULL,(Item *)NULL,
		       (ORDER *)NULL,
		       select_lex->options | thd->options |
		       SELECT_NO_JOIN_CACHE,
		       result);
    }
    else
      res= -1;					// Error is not sent
    delete result;
    close_thread_tables(thd);
    break;
  }
  case SQLCOM_MULTI_UPDATE:
    multi_update  *result;
    uint table_count;
    TABLE_LIST *auxi;
    if (check_access(thd,UPDATE_ACL,tables->db,&tables->grant.privilege))
      goto error;
    if (grant_option && check_grant(thd,UPDATE_ACL,tables))
      goto error;
    if (select_lex->item_list.elements != lex->value_list.elements)
    {
      send_error(&thd->net,ER_WRONG_VALUE_COUNT);
      DBUG_VOID_RETURN;
    }
    for (auxi=(TABLE_LIST*) tables, table_count=0 ; auxi ; auxi=auxi->next)
    {
      table_count++;
      auxi->lock_type=TL_WRITE;
    }
    if (select_lex->order_list.elements || (select_lex->select_limit && select_lex->select_limit < INT_MAX))
    {
      send_error(&thd->net,ER_NOT_ALLOWED_COMMAND); /// will have to come up with something better eventually
      DBUG_VOID_RETURN;
    }
    tables->grant.want_privilege=(SELECT_ACL & ~tables->grant.privilege);
    if ((res=open_and_lock_tables(thd,tables)))
      break;
    if (!setup_fields(thd,tables,select_lex->item_list,1,0,0) && 
	!setup_fields(thd,tables,lex->value_list,0,0,0) &&  ! thd->fatal_error &&
	(result=new multi_update(thd,tables,select_lex->item_list,lex->duplicates,
				 lex->lock_option, table_count)))
    {
      List <Item> total_list;
      List_iterator <Item> field_list(select_lex->item_list);
      List_iterator <Item> value_list(lex->value_list);
      Item *item;
      while ((item=field_list++))
	total_list.push_back(item);
      while ((item=value_list++))
	total_list.push_back(item);

      res=mysql_select(thd,tables,total_list,
		       select_lex->where,
		       (ORDER *)NULL,(ORDER *)NULL,(Item *)NULL,
		       (ORDER *)NULL,
		       select_lex->options | thd->options |
		       SELECT_NO_JOIN_CACHE,
		       result);
      delete result;
    }
    else
      res= -1;					// Error is not sent
    close_thread_tables(thd);
    break;
  case SQLCOM_DROP_TABLE:
  {
    if (check_table_access(thd,DROP_ACL,tables))
      goto error;				/* purecov: inspected */
    if (end_active_trans(thd))
      res= -1;
    else
      res = mysql_rm_table(thd,tables,lex->drop_if_exists);
  }
  break;
  case SQLCOM_DROP_INDEX:
    if (!tables->db)
      tables->db=thd->db;
    if (check_access(thd,INDEX_ACL,tables->db,&tables->grant.privilege))
      goto error;				/* purecov: inspected */
    if (grant_option && check_grant(thd,INDEX_ACL,tables))
      goto error;
    if (end_active_trans(thd))
      res= -1;
    else
      res = mysql_drop_index(thd, tables, lex->drop_list);
    break;
  case SQLCOM_SHOW_DATABASES:
#if defined(DONT_ALLOW_SHOW_COMMANDS)
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);   /* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    if ((specialflag & SPECIAL_SKIP_SHOW_DB) &&
	check_process_priv(thd))
      goto error;
    res= mysqld_show_dbs(thd, (lex->wild ? lex->wild->ptr() : NullS));
    break;
#endif
  case SQLCOM_SHOW_PROCESSLIST:
    if (!thd->priv_user[0] && check_process_priv(thd))
      break;
    mysqld_list_processes(thd,thd->master_access & PROCESS_ACL ? NullS :
			  thd->priv_user,lex->verbose);
    break;
  case SQLCOM_SHOW_STATUS:
    res= mysqld_show(thd,(lex->wild ? lex->wild->ptr() : NullS),status_vars);
    break;
  case SQLCOM_SHOW_VARIABLES:
    res= mysqld_show(thd, (lex->wild ? lex->wild->ptr() : NullS),
		     init_vars);
    break;
  case SQLCOM_SHOW_LOGS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);	/* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    {
      if (grant_option && check_access(thd, FILE_ACL, any_db))
	goto error;
      res= mysqld_show_logs(thd);
      break;
    }
#endif
  case SQLCOM_SHOW_TABLES:
    /* FALL THROUGH */
#ifdef DONT_ALLOW_SHOW_COMMANDS
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);	/* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    {
      char *db=select_lex->db ? select_lex->db : thd->db;
      if (!db)
      {
	send_error(&thd->net,ER_NO_DB_ERROR);	/* purecov: inspected */
	goto error;				/* purecov: inspected */
      }
      remove_escape(db);				// Fix escaped '_'
      if (check_db_name(db))
      {
        net_printf(&thd->net,ER_WRONG_DB_NAME, db);
        goto error;
      }
      if (check_access(thd,SELECT_ACL,db,&thd->col_access))
	goto error;				/* purecov: inspected */
      /* grant is checked in mysqld_show_tables */
      if (select_lex->options & SELECT_DESCRIBE)
        res= mysqld_extend_show_tables(thd,db,
				       (lex->wild ? lex->wild->ptr() : NullS));
      else
	res= mysqld_show_tables(thd,db,
				(lex->wild ? lex->wild->ptr() : NullS));
      break;
    }
#endif
  case SQLCOM_SHOW_OPEN_TABLES:
    res= mysqld_show_open_tables(thd,(lex->wild ? lex->wild->ptr() : NullS));
    break;
  case SQLCOM_SHOW_FIELDS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);	/* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    {
      char *db=tables->db;
      if (!*db)
      {
	send_error(&thd->net,ER_NO_DB_ERROR);	/* purecov: inspected */
	goto error;				/* purecov: inspected */
      }
      remove_escape(db);			// Fix escaped '_'
      remove_escape(tables->name);
      if (check_access(thd,SELECT_ACL | EXTRA_ACL,db,&thd->col_access))
	goto error;				/* purecov: inspected */
      tables->grant.privilege=thd->col_access;
      if (grant_option && check_grant(thd,SELECT_ACL,tables,2))
	goto error;
      res= mysqld_show_fields(thd,tables,
			      (lex->wild ? lex->wild->ptr() : NullS),
			      lex->verbose);
      break;
    }
#endif
  case SQLCOM_SHOW_KEYS:
#ifdef DONT_ALLOW_SHOW_COMMANDS
    send_error(&thd->net,ER_NOT_ALLOWED_COMMAND);	/* purecov: inspected */
    DBUG_VOID_RETURN;
#else
    {
      char *db=tables->db;
      if (!db)
      {
	send_error(&thd->net,ER_NO_DB_ERROR);	/* purecov: inspected */
	goto error;				/* purecov: inspected */
      }
      remove_escape(db);			// Fix escaped '_'
      remove_escape(tables->name);
      if (!tables->db)
	tables->db=thd->db;
      if (check_access(thd,SELECT_ACL,db,&thd->col_access))
	goto error; /* purecov: inspected */
      tables->grant.privilege=thd->col_access;
      if (grant_option && check_grant(thd,SELECT_ACL,tables,2))
	goto error;
      res= mysqld_show_keys(thd,tables);
      break;
    }
#endif
  case SQLCOM_CHANGE_DB:
    mysql_change_db(thd,select_lex->db);
    break;
  case SQLCOM_LOAD:
  {
    uint privilege= (lex->duplicates == DUP_REPLACE ?
		     INSERT_ACL | UPDATE_ACL | DELETE_ACL : INSERT_ACL);
    if (!(lex->local_file && (thd->client_capabilities & CLIENT_LOCAL_FILES)))
    {
      if (check_access(thd,privilege | FILE_ACL,tables->db))
	goto error;
    }
    else
    {
      if (check_access(thd,privilege,tables->db,&tables->grant.privilege) ||
	  grant_option && check_grant(thd,privilege,tables))
	goto error;
    }
    res=mysql_load(thd, lex->exchange, tables, lex->field_list,
		   lex->duplicates, (bool) lex->local_file, lex->lock_option);
    break;
  }
  case SQLCOM_SET_OPTION:
  {
    ulong org_options=thd->options;
    thd->options=select_lex->options;
    thd->update_lock_default= ((thd->options & OPTION_LOW_PRIORITY_UPDATES) ?
			       TL_WRITE_LOW_PRIORITY : TL_WRITE);
    thd->default_select_limit=select_lex->select_limit;
    thd->tx_isolation=lex->tx_isolation;
    DBUG_PRINT("info",("options: %ld  limit: %ld",
		       thd->options,(long) thd->default_select_limit));

    /* Check if auto_commit mode changed */
    if ((org_options ^ select_lex->options) & OPTION_NOT_AUTO_COMMIT)
    {
      if ((org_options & OPTION_NOT_AUTO_COMMIT))
      {
	/* We changed to auto_commit mode */
	thd->options&= ~(ulong) (OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE);
	thd->server_status|= SERVER_STATUS_AUTOCOMMIT;
	if (ha_commit(thd))
	{
	  res= -1;
	  break;
	}
      }
      else
      {
	thd->options&= ~(ulong) (OPTION_STATUS_NO_TRANS_UPDATE);
	thd->server_status&= ~SERVER_STATUS_AUTOCOMMIT;
      }
    }
    send_ok(&thd->net);
    break;
  }
  case SQLCOM_UNLOCK_TABLES:
    if (thd->locked_tables)
    {
      thd->lock=thd->locked_tables;
      thd->locked_tables=0;			// Will be automaticly closed
    }
    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->net);
    break;
  case SQLCOM_LOCK_TABLES:
    if (thd->locked_tables)
    {
      thd->lock=thd->locked_tables;
      thd->locked_tables=0;			// Will be automaticly closed
      close_thread_tables(thd);
    }
    if (check_db_used(thd,tables) || end_active_trans(thd))
      goto error;
    if (grant_option && check_grant(thd,SELECT_ACL | INSERT_ACL | UPDATE_ACL | DELETE_ACL,tables))
      goto error;
    thd->in_lock_tables=1;
    thd->options|= OPTION_TABLE_LOCK;
    if (!(res=open_and_lock_tables(thd,tables)))
    {
      thd->locked_tables=thd->lock;
      thd->lock=0;
      send_ok(&thd->net);
    }
    else
      thd->options&= ~(ulong) (OPTION_TABLE_LOCK);
    thd->in_lock_tables=0;
    break;
  case SQLCOM_CREATE_DB:
  {
    if (!stripp_sp(lex->name) || check_db_name(lex->name))
    {
      net_printf(&thd->net,ER_WRONG_DB_NAME, lex->name);
      break;
    }
    if (check_access(thd,CREATE_ACL,lex->name,0,1))
      break;
    res=mysql_create_db(thd,lex->name,lex->create_info.options,0);
    break;
  }
  case SQLCOM_DROP_DB:
  {
    if (!stripp_sp(lex->name) || check_db_name(lex->name))
    {
      net_printf(&thd->net,ER_WRONG_DB_NAME, lex->name);
      break;
    }
    if (check_access(thd,DROP_ACL,lex->name,0,1))
      break;
    if (thd->locked_tables || thd->active_transaction())
    {
      send_error(&thd->net,ER_LOCK_OR_ACTIVE_TRANSACTION);
      goto error;
    }
    res=mysql_rm_db(thd,lex->name,lex->drop_if_exists,0);
    break;
  }
  case SQLCOM_CREATE_FUNCTION:
    if (check_access(thd,INSERT_ACL,"mysql",0,1))
      break;
#ifdef HAVE_DLOPEN
    if (!(res = mysql_create_function(thd,&lex->udf)))
      send_ok(&thd->net);
#else
    res= -1;
#endif
    break;
  case SQLCOM_DROP_FUNCTION:
    if (check_access(thd,DELETE_ACL,"mysql",0,1))
      break;
#ifdef HAVE_DLOPEN
    if (!(res = mysql_drop_function(thd,lex->udf.name)))
      send_ok(&thd->net);
#else
    res= -1;
#endif
    break;
  case SQLCOM_REVOKE:
  case SQLCOM_GRANT:
  {
    if (check_access(thd, lex->grant | lex->grant_tot_col | GRANT_ACL,
		     tables && tables->db ? tables->db : select_lex->db,
		     tables ? &tables->grant.privilege : 0,
		     tables ? 0 : 1))
      goto error;

    /* Check that the user isn't trying to change a password for another
       user if he doesn't have UPDATE privilege to the MySQL database */

    if (thd->user)				// If not replication
    {
      LEX_USER *user;
      List_iterator <LEX_USER> user_list(lex->users_list);
      while ((user=user_list++))
      {
	if (user->password.str &&
	    (strcmp(thd->user,user->user.str) ||
	     user->host.str &&
	     my_strcasecmp(user->host.str, thd->host_or_ip)))
	{
	  if (check_access(thd, UPDATE_ACL, "mysql",0,1))
	    goto error;
	  break;			// We are allowed to do changes
	}
      }
    }
    if (tables)
    {
      if (grant_option && check_grant(thd,
				      (lex->grant | lex->grant_tot_col |
				       GRANT_ACL),
				      tables))
	goto error;
      if (!(res = mysql_table_grant(thd,tables,lex->users_list, lex->columns,
				    lex->grant,
				    lex->sql_command == SQLCOM_REVOKE)))
      {
	mysql_update_log.write(thd, thd->query, thd->query_length);
	if (mysql_bin_log.is_open())
	{
	  Query_log_event qinfo(thd, thd->query);
	  mysql_bin_log.write(&qinfo);
	}
      }
    }
    else
    {
      if (lex->columns.elements)
      {
	send_error(&thd->net,ER_ILLEGAL_GRANT_FOR_TABLE);
	res=1;
      }
      else
	res = mysql_grant(thd, select_lex->db, lex->users_list, lex->grant,
			  lex->sql_command == SQLCOM_REVOKE);
      if (!res)
      {
	mysql_update_log.write(thd, thd->query, thd->query_length);
	if (mysql_bin_log.is_open())
	{
	  Query_log_event qinfo(thd, thd->query);
	  mysql_bin_log.write(&qinfo);
	}
      }
    }
    if (mqh_used && hash_user_connections.array.buffer == 0)
      init_max_user_conn();
    break;
  }
  case SQLCOM_FLUSH:
  case SQLCOM_RESET:
    if (check_access(thd,RELOAD_ACL,any_db) || check_db_used(thd, tables))
      goto error;
    if (reload_acl_and_cache(thd, lex->type, tables))
      send_error(&thd->net,0);
    else
      send_ok(&thd->net);
    break;
  case SQLCOM_KILL:
    kill_one_thread(thd,lex->thread_id);
    break;
  case SQLCOM_SHOW_GRANTS:
    res=0;
    if ((thd->priv_user &&
	 !strcmp(thd->priv_user,lex->grant_user->user.str)) ||
	!check_access(thd, SELECT_ACL, "mysql",0,1))
    {
      res = mysql_show_grants(thd,lex->grant_user);
    }
    break;
  case SQLCOM_HA_OPEN:
    if (check_db_used(thd,tables) ||
	check_table_access(thd,SELECT_ACL, tables))
      goto error;
    res = mysql_ha_open(thd, tables);
    break;
  case SQLCOM_HA_CLOSE:
    if (check_db_used(thd,tables))
      goto error;
    res = mysql_ha_close(thd, tables);
    break;
  case SQLCOM_HA_READ:
    if (check_db_used(thd,tables) ||
	check_table_access(thd,SELECT_ACL, tables))
      goto error;
    res = mysql_ha_read(thd, tables, lex->ha_read_mode, lex->backup_dir,
			lex->insert_list, lex->ha_rkey_mode, select_lex->where,
			select_lex->select_limit, select_lex->offset_limit);
    break;

  case SQLCOM_BEGIN:
    if (thd->locked_tables)
    {
      thd->lock=thd->locked_tables;
      thd->locked_tables=0;			// Will be automaticly closed
      close_thread_tables(thd);			// Free tables
    }
    if (end_active_trans(thd))
    {
      res= -1;
    }
    else
    {
      thd->options= ((thd->options & (ulong) ~(OPTION_STATUS_NO_TRANS_UPDATE)) |
		     OPTION_BEGIN);
      thd->server_status|= SERVER_STATUS_IN_TRANS;
      send_ok(&thd->net);
    }
    break;
  case SQLCOM_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->options&= ~(ulong) (OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE);
    thd->server_status&= ~SERVER_STATUS_IN_TRANS;
    if (!ha_commit(thd))
    {
      send_ok(&thd->net);
    }
    else
      res= -1;
    break;
  }
  case SQLCOM_ROLLBACK:
    thd->server_status&= ~SERVER_STATUS_IN_TRANS;
    if (!ha_rollback(thd))
    {
      if (thd->options & OPTION_STATUS_NO_TRANS_UPDATE)
	send_warning(&thd->net,ER_WARNING_NOT_COMPLETE_ROLLBACK,0);
      else
	send_ok(&thd->net);
    }
    else
      res= -1;
    thd->options&= ~(ulong) (OPTION_BEGIN | OPTION_STATUS_NO_TRANS_UPDATE);
    break;
  default:					/* Impossible */
    send_ok(&thd->net);
    break;
  }
  thd->proc_info="query end";			// QQ
  if (res < 0)
    send_error(&thd->net,thd->killed ? ER_SERVER_SHUTDOWN : 0);

error:
  DBUG_VOID_RETURN;
}


/****************************************************************************
** Get the user (global) and database privileges for all used tables
** Returns true (error) if we can't get the privileges and we don't use
** table/column grants.
** The idea of EXTRA_ACL is that one will be granted access to the table if
** one has the asked privilege on any column combination of the table; For
** example to be able to check a table one needs to have SELECT privilege on
** any column of the table.
****************************************************************************/

bool
check_access(THD *thd,uint want_access,const char *db, uint *save_priv,
	     bool dont_check_global_grants, bool no_errors)
{
  uint db_access,dummy;
  if (save_priv)
    *save_priv=0;
  else
    save_priv= &dummy;

  if ((!db || !db[0]) && !thd->db && !dont_check_global_grants)
  {
    if (!no_errors)
      send_error(&thd->net,ER_NO_DB_ERROR);	/* purecov: tested */
    return TRUE;				/* purecov: tested */
  }

  if ((thd->master_access & want_access) == want_access)
  {
    *save_priv=thd->master_access;
    return FALSE;
  }
  if ((want_access & ~thd->master_access) & ~(DB_ACLS | EXTRA_ACL) ||
      ! db && dont_check_global_grants)
  {						// We can never grant this
    if (!no_errors)
      net_printf(&thd->net,ER_ACCESS_DENIED_ERROR,
		 thd->priv_user,
		 thd->host_or_ip,
		 thd->password ? ER(ER_YES) : ER(ER_NO));/* purecov: tested */
    return TRUE;				/* purecov: tested */
  }

  if (db == any_db)
    return FALSE;				// Allow select on anything

  if (db && (!thd->db || strcmp(db,thd->db)))
    db_access=acl_get(thd->host, thd->ip, (char*) &thd->remote.sin_addr,
		      thd->priv_user, db); /* purecov: inspected */
  else
    db_access=thd->db_access;
  want_access &= ~EXTRA_ACL;			// Remove SHOW attribute
  db_access= ((*save_priv=(db_access | thd->master_access)) & want_access);

  /* grant_option is set if there exists a single table or column grant */
  if (db_access == want_access ||
      ((grant_option && !dont_check_global_grants) &&
       !(want_access & ~TABLE_ACLS)))
    return FALSE;				/* Ok */
  if (!no_errors)
    net_printf(&thd->net,ER_DBACCESS_DENIED_ERROR,
	       thd->priv_user,
	       thd->host_or_ip,
	       db ? db : thd->db ? thd->db : "unknown"); /* purecov: tested */
  return TRUE;					/* purecov: tested */
}


bool check_process_priv(THD *thd)
{
  return (check_access(thd ? thd : current_thd,PROCESS_ACL,any_db));
}


/*
** Check the privilege for all used tables.  Table privileges are cached
** in the table list for GRANT checking
*/

bool
check_table_access(THD *thd,uint want_access,TABLE_LIST *tables,
		   bool no_errors)
{
  uint found=0,found_access=0;
  TABLE_LIST *org_tables=tables;
  for (; tables ; tables=tables->next)
  {
    if ((thd->master_access & want_access) == (want_access & ~EXTRA_ACL) &&
	thd->db)
      tables->grant.privilege= want_access;
    else if (tables->db && tables->db == thd->db)
    {
      if (found && !grant_option)		// db already checked
	tables->grant.privilege=found_access;
      else
      {
	if (check_access(thd,want_access,tables->db,&tables->grant.privilege,
			 0, no_errors))
	  return TRUE;				// Access denied
	found_access=tables->grant.privilege;
	found=1;
      }
    }
    else if (check_access(thd,want_access,tables->db,&tables->grant.privilege,
			  0, no_errors))
      return TRUE;				// Access denied
  }
  if (grant_option)
    return check_grant(thd,want_access & ~EXTRA_ACL,org_tables,
		       test(want_access & EXTRA_ACL), no_errors);
  return FALSE;
}


static bool check_db_used(THD *thd,TABLE_LIST *tables)
{
  for (; tables ; tables=tables->next)
  {
    if (!tables->db)
    {
      if (!(tables->db=thd->db))
      {
	send_error(&thd->net,ER_NO_DB_ERROR);	/* purecov: tested */
	return TRUE;				/* purecov: tested */
      }
    }
  }
  return FALSE;
}


static bool check_merge_table_access(THD *thd, char *db,
				     TABLE_LIST *table_list)
{
  int error=0;
  if (table_list)
  {
    /* Check that all tables use the current database */
    TABLE_LIST *tmp;
    for (tmp=table_list; tmp ; tmp=tmp->next)
    {
      if (!tmp->db || !tmp->db[0])
	tmp->db=db;
      else if (strcmp(tmp->db,db))
      {
	send_error(&thd->net,ER_UNION_TABLES_IN_DIFFERENT_DIR);
	return 1;
      }
    }
    error=check_table_access(thd, SELECT_ACL | UPDATE_ACL | DELETE_ACL,
			     table_list);
  }
  return error;
}


/****************************************************************************
	Check stack size; Send error if there isn't enough stack to continue
****************************************************************************/

#if STACK_DIRECTION < 0
#define used_stack(A,B) (long) (A - B)
#else
#define used_stack(A,B) (long) (B - A)
#endif

bool check_stack_overrun(THD *thd,char *buf __attribute__((unused)))
{
  long stack_used;
  if ((stack_used=used_stack(thd->thread_stack,(char*) &stack_used)) >=
      (long) thread_stack_min)
  {
    sprintf(errbuff[0],ER(ER_STACK_OVERRUN),stack_used,thread_stack);
    my_message(ER_STACK_OVERRUN,errbuff[0],MYF(0));
    thd->fatal_error=1;
    return 1;
  }
  return 0;
}

#define MY_YACC_INIT 1000			// Start with big alloc
#define MY_YACC_MAX  32000			// Because of 'short'

bool my_yyoverflow(short **yyss, YYSTYPE **yyvs, int *yystacksize)
{
  LEX	*lex=current_lex;
  int  old_info=0;
  if ((uint) *yystacksize >= MY_YACC_MAX)
    return 1;
  if (!lex->yacc_yyvs)
    old_info= *yystacksize;
  *yystacksize= set_zone((*yystacksize)*2,MY_YACC_INIT,MY_YACC_MAX);
  if (!(lex->yacc_yyvs= (char*)
	my_realloc((gptr) lex->yacc_yyvs,
		   *yystacksize*sizeof(**yyvs),
		   MYF(MY_ALLOW_ZERO_PTR | MY_FREE_ON_ERROR))) ||
      !(lex->yacc_yyss= (char*)
	my_realloc((gptr) lex->yacc_yyss,
		   *yystacksize*sizeof(**yyss),
		   MYF(MY_ALLOW_ZERO_PTR | MY_FREE_ON_ERROR))))
    return 1;
  if (old_info)
  {						// Copy old info from stack
    memcpy(lex->yacc_yyss, (gptr) *yyss, old_info*sizeof(**yyss));
    memcpy(lex->yacc_yyvs, (gptr) *yyvs, old_info*sizeof(**yyvs));
  }
  *yyss=(short*) lex->yacc_yyss;
  *yyvs=(YYSTYPE*) lex->yacc_yyvs;
  return 0;
}


/****************************************************************************
	Initialize global thd variables needed for query
****************************************************************************/

static void
mysql_init_query(THD *thd)
{
  DBUG_ENTER("mysql_init_query");
  thd->lex.select_lex.item_list.empty();
  thd->lex.value_list.empty();
  thd->lex.select_lex.table_list.elements=0;
  thd->free_list=0;  thd->lex.union_option=0;
  thd->lex.select = &thd->lex.select_lex;
  thd->lex.select_lex.table_list.first=0;
  thd->lex.select_lex.table_list.next= (byte**) &thd->lex.select_lex.table_list.first;
  thd->lex.select_lex.next=0;
  thd->fatal_error=0;				// Safety
  thd->last_insert_id_used=thd->query_start_used=thd->insert_id_used=0;
  thd->sent_row_count=thd->examined_row_count=0;
  thd->safe_to_cache_query=1;
  DBUG_VOID_RETURN;
}

void
mysql_init_select(LEX *lex)
{
  SELECT_LEX *select_lex = lex->select;
  select_lex->where=select_lex->having=0;
  select_lex->select_limit=lex->thd->default_select_limit;
  select_lex->offset_limit=0;
  select_lex->options=0;
  select_lex->linkage=UNSPECIFIED_TYPE;
  lex->exchange = 0;
  lex->proc_list.first=0;
  select_lex->order_list.elements=select_lex->group_list.elements=0;
  select_lex->order_list.first=0;
  select_lex->order_list.next= (byte**) &select_lex->order_list.first;
  select_lex->group_list.first=0;
  select_lex->group_list.next= (byte**) &select_lex->group_list.first;
  select_lex->next = (SELECT_LEX *)NULL; 
}

bool
mysql_new_select(LEX *lex)
{
  SELECT_LEX *select_lex = (SELECT_LEX *) lex->thd->calloc(sizeof(SELECT_LEX));
  if (!select_lex)
    return 1;
  lex->select->next=select_lex; 
  lex->select=select_lex;
  select_lex->table_list.next= (byte**) &select_lex->table_list.first;
  select_lex->item_list.empty();
  select_lex->when_list.empty(); 
  select_lex->expr_list.empty();
  select_lex->interval_list.empty(); 
  select_lex->use_index.empty();
  select_lex->ftfunc_list.empty();
  return 0;
}

void mysql_init_multi_delete(LEX *lex)
{
  lex->sql_command =  SQLCOM_DELETE_MULTI;
  mysql_init_select(lex);
  lex->select->select_limit=HA_POS_ERROR;
  lex->auxilliary_table_list=lex->select_lex.table_list;
  lex->select->table_list.elements=0; 
  lex->select->table_list.first=0;
  lex->select->table_list.next= (byte**) &(lex->select->table_list.first);
}

void
mysql_parse(THD *thd,char *inBuf,uint length)
{
  DBUG_ENTER("mysql_parse");

  mysql_init_query(thd);
  thd->query_length = length;
  if (query_cache.send_result_to_client(thd, inBuf, length) <= 0)
  {
    LEX *lex=lex_start(thd, (uchar*) inBuf, length);
    if (!yyparse() && ! thd->fatal_error)
    {
      mysql_execute_command();
      query_cache_end_of_result(&thd->net);
    }
    else
      query_cache_abort(&thd->net);
    thd->proc_info="freeing items";
    free_items(thd);  /* Free strings used by items */
    lex_end(lex);
  }
  DBUG_VOID_RETURN;
}


inline static void
link_in_list(SQL_LIST *list,byte *element,byte **next)
{
  list->elements++;
  (*list->next)=element;
  list->next=next;
  *next=0;
}


/*****************************************************************************
** Store field definition for create
** Return 0 if ok
******************************************************************************/

bool add_field_to_list(char *field_name, enum_field_types type,
		       char *length, char *decimals,
		       uint type_modifier, Item *default_value,char *change,
		       TYPELIB *interval)
{
  register create_field *new_field;
  THD	*thd=current_thd;
  LEX  *lex= &thd->lex;
  uint allowed_type_modifier=0;
  DBUG_ENTER("add_field_to_list");

  if (strlen(field_name) > NAME_LEN)
  {
    net_printf(&thd->net, ER_TOO_LONG_IDENT, field_name); /* purecov: inspected */
    DBUG_RETURN(1);				/* purecov: inspected */
  }
  if (type_modifier & PRI_KEY_FLAG)
  {
    lex->col_list.push_back(new key_part_spec(field_name,0));
    lex->key_list.push_back(new Key(Key::PRIMARY,NullS,
				    lex->col_list));
    lex->col_list.empty();
  }
  if (type_modifier & (UNIQUE_FLAG | UNIQUE_KEY_FLAG))
  {
    lex->col_list.push_back(new key_part_spec(field_name,0));
    lex->key_list.push_back(new Key(Key::UNIQUE,NullS,
				    lex->col_list));
    lex->col_list.empty();
  }

  if (default_value && default_value->type() == Item::NULL_ITEM)
  {
    if ((type_modifier & (NOT_NULL_FLAG | AUTO_INCREMENT_FLAG)) ==
	NOT_NULL_FLAG)
    {
      net_printf(&thd->net,ER_INVALID_DEFAULT,field_name);
      DBUG_RETURN(1);
    }
    default_value=0;
  }
  if (!(new_field=new create_field()))
    DBUG_RETURN(1);
  new_field->field=0;
  new_field->field_name=field_name;
  new_field->def= (type_modifier & AUTO_INCREMENT_FLAG ? 0 : default_value);
  new_field->flags= type_modifier;
  new_field->unireg_check= (type_modifier & AUTO_INCREMENT_FLAG ?
			    Field::NEXT_NUMBER : Field::NONE);
  new_field->decimals= decimals ? (uint) set_zone(atoi(decimals),0,
						  NOT_FIXED_DEC-1) : 0;
  new_field->sql_type=type;
  new_field->length=0;
  new_field->change=change;
  new_field->interval=0;
  new_field->pack_length=0;
  if (length)
    if (!(new_field->length= (uint) atoi(length)))
      length=0; /* purecov: inspected */
  uint sign_len=type_modifier & UNSIGNED_FLAG ? 0 : 1;

  if (new_field->length && new_field->decimals &&
      new_field->length < new_field->decimals+2 &&
      new_field->decimals != NOT_FIXED_DEC)
    new_field->length=new_field->decimals+2; /* purecov: inspected */

  switch (type) {
  case FIELD_TYPE_TINY:
    if (!length) new_field->length=3+sign_len;
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    break;
  case FIELD_TYPE_SHORT:
    if (!length) new_field->length=5+sign_len;
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    break;
  case FIELD_TYPE_INT24:
    if (!length) new_field->length=8+sign_len;
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    break;
  case FIELD_TYPE_LONG:
    if (!length) new_field->length=10+sign_len;
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    break;
  case FIELD_TYPE_LONGLONG:
    if (!length) new_field->length=20;
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    break;
  case FIELD_TYPE_STRING:
  case FIELD_TYPE_VAR_STRING:
  case FIELD_TYPE_NULL:
    break;
  case FIELD_TYPE_DECIMAL:
    if (!length)
      new_field->length = 10;			// Default length for DECIMAL
    new_field->length+=sign_len;
    if (new_field->decimals)
      new_field->length++;
    break;
  case FIELD_TYPE_BLOB:
  case FIELD_TYPE_TINY_BLOB:
  case FIELD_TYPE_LONG_BLOB:
  case FIELD_TYPE_MEDIUM_BLOB:
    if (default_value)				// Allow empty as default value
    {
      String str,*res;
      res=default_value->val_str(&str);
      if (res->length())
      {
	net_printf(&thd->net,ER_BLOB_CANT_HAVE_DEFAULT,field_name); /* purecov: inspected */
	DBUG_RETURN(1); /* purecov: inspected */
      }
      new_field->def=0;
    }
    new_field->flags|=BLOB_FLAG;
    break;
  case FIELD_TYPE_YEAR:
    if (!length || new_field->length != 2)
      new_field->length=4;			// Default length
    new_field->flags|= ZEROFILL_FLAG | UNSIGNED_FLAG;
    break;
  case FIELD_TYPE_FLOAT:
    /* change FLOAT(precision) to FLOAT or DOUBLE */
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    if (length && !decimals)
    {
      uint tmp_length=new_field->length;
      if (tmp_length > PRECISION_FOR_DOUBLE)
      {
	net_printf(&thd->net,ER_WRONG_FIELD_SPEC,field_name);
	DBUG_RETURN(1);
      }
      else if (tmp_length > PRECISION_FOR_FLOAT)
      {
	new_field->sql_type=FIELD_TYPE_DOUBLE;
	new_field->length=DBL_DIG+7;			// -[digits].E+###
      }
      else
	new_field->length=FLT_DIG+6;			// -[digits].E+##
      new_field->decimals= NOT_FIXED_DEC;
      break;
    }
    if (!length)
    {
      new_field->length =  FLT_DIG+6;
      new_field->decimals= NOT_FIXED_DEC;
    }
    break;
  case FIELD_TYPE_DOUBLE:
    allowed_type_modifier= AUTO_INCREMENT_FLAG;
    if (!length)
    {
      new_field->length = DBL_DIG+7;
      new_field->decimals=NOT_FIXED_DEC;
    }
    break;
  case FIELD_TYPE_TIMESTAMP:
    if (!length)
      new_field->length= 14;			// Full date YYYYMMDDHHMMSS
    else
    {
      new_field->length=((new_field->length+1)/2)*2; /* purecov: inspected */
      new_field->length= min(new_field->length,14); /* purecov: inspected */
    }
    new_field->flags|= ZEROFILL_FLAG | UNSIGNED_FLAG | NOT_NULL_FLAG;
    break;
  case FIELD_TYPE_DATE:				// Old date type
    if (protocol_version != PROTOCOL_VERSION-1)
      new_field->sql_type=FIELD_TYPE_NEWDATE;
    /* fall trough */
  case FIELD_TYPE_NEWDATE:
    new_field->length=10;
    break;
  case FIELD_TYPE_TIME:
    new_field->length=10;
    break;
  case FIELD_TYPE_DATETIME:
    new_field->length=19;
    break;
  case FIELD_TYPE_SET:
    {
      if (interval->count > sizeof(longlong)*8)
      {
	net_printf(&thd->net,ER_TOO_BIG_SET,field_name); /* purecov: inspected */
	DBUG_RETURN(1);				/* purecov: inspected */
      }
      new_field->pack_length=(interval->count+7)/8;
      if (new_field->pack_length > 4)
	new_field->pack_length=8;
      new_field->interval=interval;
      new_field->length=0;
      for (const char **pos=interval->type_names; *pos ; pos++)
	new_field->length+=(uint) strlen(*pos)+1;
      new_field->length--;
      set_if_smaller(new_field->length,MAX_FIELD_WIDTH-1);
      if (default_value)
      {
	thd->cuted_fields=0;
	String str,*res;
	res=default_value->val_str(&str);
	(void) find_set(interval,res->ptr(),res->length());
	if (thd->cuted_fields)
	{
	  net_printf(&thd->net,ER_INVALID_DEFAULT,field_name);
	  DBUG_RETURN(1);
	}
      }
    }
    break;
  case FIELD_TYPE_ENUM:
    {
      new_field->interval=interval;
      new_field->pack_length=interval->count < 256 ? 1 : 2; // Should be safe
      new_field->length=(uint) strlen(interval->type_names[0]);
      for (const char **pos=interval->type_names+1; *pos ; pos++)
      {
	uint length=(uint) strlen(*pos);
	set_if_bigger(new_field->length,length);
      }
      set_if_smaller(new_field->length,MAX_FIELD_WIDTH-1);
      if (default_value)
      {
	String str,*res;
	res=default_value->val_str(&str);
	if (!find_enum(interval,res->ptr(),res->length()))
	{
	  net_printf(&thd->net,ER_INVALID_DEFAULT,field_name);
	  DBUG_RETURN(1);
	}
      }
      break;
    }
  }

  if (new_field->length >= MAX_FIELD_WIDTH ||
      (!new_field->length && !(new_field->flags & BLOB_FLAG) &&
       type != FIELD_TYPE_STRING))
  {
    net_printf(&thd->net,ER_TOO_BIG_FIELDLENGTH,field_name,
	       MAX_FIELD_WIDTH-1);		/* purecov: inspected */
    DBUG_RETURN(1);				/* purecov: inspected */
  }
  type_modifier&= AUTO_INCREMENT_FLAG;
  if ((~allowed_type_modifier) & type_modifier)
  {
    net_printf(&thd->net,ER_WRONG_FIELD_SPEC,field_name);
    DBUG_RETURN(1);
  }
  if (!new_field->pack_length)
    new_field->pack_length=calc_pack_length(new_field->sql_type ==
					    FIELD_TYPE_VAR_STRING ?
					    FIELD_TYPE_STRING :
					    new_field->sql_type,
					    new_field->length);
  lex->create_list.push_back(new_field);
  lex->last_field=new_field;
  DBUG_RETURN(0);
}

/* Store position for column in ALTER TABLE .. ADD column */

void store_position_for_column(const char *name)
{
  current_lex->last_field->after=my_const_cast(char*) (name);
}

bool
add_proc_to_list(Item *item)
{
  ORDER *order;
  Item	**item_ptr;

  if (!(order = (ORDER *) sql_alloc(sizeof(ORDER)+sizeof(Item*))))
    return 1;
  item_ptr = (Item**) (order+1);
  *item_ptr= item;
  order->item=item_ptr;
  order->free_me=0;
  link_in_list(&current_lex->proc_list,(byte*) order,(byte**) &order->next);
  return 0;
}


/* Fix escaping of _, % and \ in database and table names (for ODBC) */

static void remove_escape(char *name)
{
  if (!*name)					// For empty DB names
    return;
  char *to;
#ifdef USE_MB
  char *strend=name+(uint) strlen(name);
#endif
  for (to=name; *name ; name++)
  {
#ifdef USE_MB
    int l;
/*    if ((l = ismbchar(name, name+MBMAXLEN))) { Wei He: I think it's wrong */
    if (use_mb(default_charset_info) &&
        (l = my_ismbchar(default_charset_info, name, strend)))
    {
	while (l--)
	    *to++ = *name++;
	name--;
	continue;
    }
#endif
    if (*name == '\\' && name[1])
      name++;					// Skip '\\'
    *to++= *name;
  }
  *to=0;
}

/****************************************************************************
** save order by and tables in own lists
****************************************************************************/


bool add_to_list(SQL_LIST &list,Item *item,bool asc)
{
  ORDER *order;
  Item	**item_ptr;
  DBUG_ENTER("add_to_list");
  if (!(order = (ORDER *) sql_alloc(sizeof(ORDER)+sizeof(Item*))))
    DBUG_RETURN(1);
  item_ptr = (Item**) (order+1);
  *item_ptr=item;
  order->item= item_ptr;
  order->asc = asc;
  order->free_me=0;
  order->used=0;
  link_in_list(&list,(byte*) order,(byte**) &order->next);
  DBUG_RETURN(0);
}


TABLE_LIST *add_table_to_list(Table_ident *table, LEX_STRING *alias,
			      bool updating,
			      thr_lock_type flags,
			      List<String> *use_index,
			      List<String> *ignore_index
			      )
{
  register TABLE_LIST *ptr;
  THD	*thd=current_thd;
  char *alias_str;
  DBUG_ENTER("add_table_to_list");

  if (!table)
    DBUG_RETURN(0);				// End of memory
  alias_str= alias ? alias->str : table->table.str;
  if (table->table.length > NAME_LEN ||
      check_table_name(table->table.str,table->table.length) ||
      table->db.str && check_db_name(table->db.str))
  {
    net_printf(&thd->net,ER_WRONG_TABLE_NAME,table->table.str);
    DBUG_RETURN(0);
  }

  if (!alias)					/* Alias is case sensitive */
    if (!(alias_str=thd->memdup(alias_str,table->table.length+1)))
      DBUG_RETURN(0);
    
  if (!(ptr = (TABLE_LIST *) thd->calloc(sizeof(TABLE_LIST))))
    DBUG_RETURN(0);				/* purecov: inspected */
  ptr->db= table->db.str ? table->db.str : (thd->db ? thd->db : (char*) "");
  ptr->name=alias_str;
  if (lower_case_table_names)
  {
    casedn_str(ptr->db);
    casedn_str(table->table.str);
  }
  ptr->real_name=table->table.str;
  ptr->lock_type=flags;
  ptr->updating=updating;
  if (use_index)
    ptr->use_index=(List<String> *) thd->memdup((gptr) use_index,
					       sizeof(*use_index));
  if (ignore_index)
    ptr->ignore_index=(List<String> *) thd->memdup((gptr) ignore_index,
						   sizeof(*ignore_index));

  /* check that used name is unique */
  if (flags != TL_IGNORE)
  {
    for (TABLE_LIST *tables=(TABLE_LIST*) thd->lex.select->table_list.first ;
	 tables ;
	 tables=tables->next)
    {
      if (!strcmp(alias_str,tables->name) && !strcmp(ptr->db, tables->db))
      {
	net_printf(&thd->net,ER_NONUNIQ_TABLE,alias_str); /* purecov: tested */
	DBUG_RETURN(0);				/* purecov: tested */
      }
    }
  }
  link_in_list(&thd->lex.select->table_list,(byte*) ptr,(byte**) &ptr->next);
  DBUG_RETURN(ptr);
}


/*
** This is used for UNION to create a new table list of all used tables
** The table_list->table entry in all used tables are set to point
** to the entries in this list.
*/

static bool create_total_list(THD *thd, LEX *lex, TABLE_LIST **result)
{
  /* Handle the case when we are not using union */
  if (!lex->select_lex.next)
  {
    *result= (TABLE_LIST*) lex->select_lex.table_list.first;
    return 0;
  }

  SELECT_LEX *sl;
  TABLE_LIST **new_table_list= result, *aux;

  *new_table_list=0;				// end result list
  for (sl= &lex->select_lex; sl; sl=sl->next)
  {
    if (sl->order_list.first && sl->next && !sl->braces)
    {
      net_printf(&thd->net,ER_WRONG_USAGE,"UNION","ORDER BY");
      return 1;
    }
    if ((aux= (TABLE_LIST*) sl->table_list.first))
    {
      TABLE_LIST *next;
      for (; aux; aux=next)
      {
	TABLE_LIST *cursor;
	next= aux->next;
	for (cursor= *result; cursor; cursor=cursor->next)
	  if (!strcmp(cursor->db,aux->db) &&
	      !strcmp(cursor->real_name,aux->real_name) &&
	      !strcmp(cursor->name, aux->name))
	    break;
	if (!cursor)
	{
	  /* Add not used table to the total table list */
	  aux->lock_type= lex->lock_option;
	  if (!(cursor = (TABLE_LIST *) thd->memdup((char*) aux,
						    sizeof(*aux))))
	  {
	    send_error(&thd->net,0);
	    return 1;
	  }
	  *new_table_list= cursor;
	  new_table_list= &cursor->next;
	  *new_table_list=0;			// end result list
	}
	else
	  aux->shared=1;			// Mark that it's used twice
	aux->table=(TABLE *) cursor;
      }
    }
  }
  return 0;
}


void add_join_on(TABLE_LIST *b,Item *expr)
{
  if (!b->on_expr)
    b->on_expr=expr;
  else
  {
    // This only happens if you have both a right and left join
    b->on_expr=new Item_cond_and(b->on_expr,expr);
  }
}


void add_join_natural(TABLE_LIST *a,TABLE_LIST *b)
{
  b->natural_join=a;
}

	/* Check if name is used in table list */

static bool check_dup(const char *db, const char *name, TABLE_LIST *tables)
{
  for (; tables ; tables=tables->next)
    if (!strcmp(name,tables->real_name) && !strcmp(db,tables->db))
      return 1;
  return 0;
}

bool reload_acl_and_cache(THD *thd, ulong options, TABLE_LIST *tables)
{
  bool result=0;

  select_errors=0;				/* Write if more errors */
  // mysql_log.flush();				// Flush log
  if (options & REFRESH_GRANT)
  {
    acl_reload();
    grant_reload();
  }
  if (options & REFRESH_LOG)
  {
    mysql_log.new_file();
    mysql_update_log.new_file();
    mysql_bin_log.new_file();
    mysql_slow_log.new_file();
    if (ha_flush_logs())
      result=1;
  }
  if (options & REFRESH_QUERY_CACHE_FREE)
  {
    query_cache.pack();				// FLUSH QUERY CACHE
    options &= ~REFRESH_QUERY_CACHE; //don't flush all cache, just free memory
  }
  if (options & (REFRESH_TABLES | REFRESH_QUERY_CACHE))
  {
    query_cache.flush();			// RESET QUERY CACHE
  }
  if (options & (REFRESH_TABLES | REFRESH_READ_LOCK))
  {
    if ((options & REFRESH_READ_LOCK) && thd)
    {
      if (lock_global_read_lock(thd))
	return 1;
    }
    result=close_cached_tables(thd,(options & REFRESH_FAST) ? 0 : 1, tables);
  }
  if (options & REFRESH_HOSTS)
    hostname_cache_refresh();
  if (options & REFRESH_STATUS)
    refresh_status();
  if (options & REFRESH_THREADS)
    flush_thread_cache();
  if (options & REFRESH_MASTER)
    reset_master();
  if (options & REFRESH_SLAVE)
    reset_slave();
#ifdef OPENSSL
  if (options & REFRESH_DES_KEY_FILE)
  {
    if (des_key_file)
      result=load_des_key_file(des_key_file);
  }
#endif
  return result;
}


void kill_one_thread(THD *thd, ulong id)
{
  VOID(pthread_mutex_lock(&LOCK_thread_count)); // For unlink from list
  I_List_iterator<THD> it(threads);
  THD *tmp;
  uint error=ER_NO_SUCH_THREAD;
  while ((tmp=it++))
  {
    if (tmp->thread_id == id)
    {
      if ((thd->master_access & PROCESS_ACL) ||
	  !strcmp(thd->user,tmp->user))
      {
	tmp->prepare_to_die();
	error=0;
      }
      else
	error=ER_KILL_DENIED_ERROR;
      break;					// Found thread
    }
  }
  VOID(pthread_mutex_unlock(&LOCK_thread_count));
  if (!error)
    send_ok(&thd->net);
  else
    net_printf(&thd->net,error,id);
}

/* Clear most status variables */

static void refresh_status(void)
{
  pthread_mutex_lock(&THR_LOCK_keycache);
  pthread_mutex_lock(&LOCK_status);
  for (struct show_var_st *ptr=status_vars; ptr->name; ptr++)
  {
    if (ptr->type == SHOW_LONG)
      *(ulong*) ptr->value=0;
  }
  pthread_mutex_unlock(&LOCK_status);
  pthread_mutex_unlock(&THR_LOCK_keycache);
}


	/* If pointer is not a null pointer, append filename to it */

static bool append_file_to_dir(THD *thd, char **filename_ptr, char *table_name)
{
  char buff[FN_REFLEN],*ptr, *end;
  if (!*filename_ptr)
    return 0;					// nothing to do

  /* Check that the filename is not too long and it's a hard path */
  if (strlen(*filename_ptr)+strlen(table_name) >= FN_REFLEN-1 ||
      !test_if_hard_path(*filename_ptr))
  {
    my_error(ER_WRONG_TABLE_NAME, MYF(0), *filename_ptr);
    return 1;
  }
  /* Fix is using unix filename format on dos */
  strmov(buff,*filename_ptr);
  end=convert_dirname(buff, *filename_ptr, NullS);
  if (!(ptr=thd->alloc((uint) (end-buff)+(uint) strlen(table_name)+1)))
    return 1;					// End of memory
  *filename_ptr=ptr;
  strxmov(ptr,buff,table_name,NullS);
  return 0;
}