/*
   Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

   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; version 2 of the License.

   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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

/*
  Functions to create a unireg form-file from a FIELD and a fieldname-fieldinfo
  struct.
  In the following functions FIELD * is an ordinary field-structure with
  the following exeptions:
    sc_length,typepos,row,kol,dtype,regnr and field need not to be set.
    str is a (long) to record position where 0 is the first position.
*/

#include "unireg.h"
#include "table.h"
#include "sql_class.h"                        // THD, Internal_error_handler
#include "partition_info.h"                   // partition_info
#include "sql_table.h"                        // validate_comment_length   

#include "pfs_file_provider.h"
#include "mysql/psi/mysql_file.h"

#include <algorithm>

using std::min;
using std::max;

#define FCOMP			17		/* Bytes for a packed field */
#define SC_INFO_LENGTH 4		/* Form format constant */
#define TE_INFO_LENGTH 3
#define MTYP_NOEMPTY_BIT 128

static uchar * pack_screens(List<Create_field> &create_fields,
			    uint *info_length, uint *screens, bool small_file);
static uint pack_keys(uchar *keybuff,uint key_count, KEY *key_info,
                      ulong data_offset);
static bool pack_header(uchar *forminfo,enum legacy_db_type table_type,
			List<Create_field> &create_fields,
			uint info_length, uint screens, uint table_options,
			ulong data_offset, handler *file);
static uint get_interval_id(uint *,List<Create_field> &, Create_field *);
static bool pack_fields(File file, List<Create_field> &create_fields,
                        ulong data_offset);
static bool make_empty_rec(THD *thd, int file,
			   uint table_options,
			   List<Create_field> &create_fields,
			   uint reclength, ulong data_offset,
                           handler *handler);
/**
  An interceptor to hijack ER_TOO_MANY_FIELDS error from
  pack_screens and retry again without UNIREG screens.

  XXX: what is a UNIREG  screen?
*/

class Pack_header_error_handler: public Internal_error_handler
{
  bool m_is_handled;
public:
  virtual bool handle_condition(THD *thd,
                                uint sql_errno,
                                const char* sqlstate,
                                Sql_condition::enum_severity_level *level,
                                const char* msg)
  {
    m_is_handled= (sql_errno == ER_TOO_MANY_FIELDS);
    return m_is_handled;
  }
  Pack_header_error_handler() :m_is_handled(false) {}
  bool is_handled() const { return m_is_handled; }
};


/*
  Create a frm (table definition) file

  SYNOPSIS
    mysql_create_frm()
    thd			Thread handler
    file_name		Path for file (including database and .frm)
    db                  Name of database
    table               Name of table
    create_info		create info parameters
    create_fields	Fields to create
    keys		number of keys to create
    key_info		Keys to create
    db_file		Handler to use. May be zero, in which case we use
			create_info->db_type
  RETURN
    false  ok
    true   error
*/

bool mysql_create_frm(THD *thd, const char *file_name,
                      const char *db, const char *table,
		      HA_CREATE_INFO *create_info,
		      List<Create_field> &create_fields,
		      uint keys, KEY *key_info,
		      handler *db_file)
{
  LEX_STRING str_db_type;
  uint reclength, info_length, screens, key_info_length, maxlength, i;
  ulong key_buff_length;
  File file;
  ulong filepos, data_offset;
  uchar fileinfo[64],forminfo[288],*keybuff, *forminfo_p= forminfo;
  uchar *screen_buff= NULL;
  char buff[128];
  partition_info *part_info= thd->work_part_info;
  Pack_header_error_handler pack_header_error_handler;
  int error;
  const uint format_section_header_size= 8;
  uint format_section_length;
  size_t tablespace_length= 0;
  DBUG_ENTER("mysql_create_frm");

  DBUG_ASSERT(*fn_rext((char*)file_name)); // Check .frm extension

  if (!(screen_buff=pack_screens(create_fields,&info_length,&screens,0)))
    DBUG_RETURN(1);
  DBUG_ASSERT(db_file != NULL);

 /* If fixed row records, we need one bit to check for deleted rows */
  if (!(create_info->table_options & HA_OPTION_PACK_RECORD))
    create_info->null_bits++;
  data_offset= (create_info->null_bits + 7) / 8;

  thd->push_internal_handler(&pack_header_error_handler);

  error= pack_header(forminfo, ha_legacy_type(create_info->db_type),
                     create_fields,info_length,
                     screens, create_info->table_options,
                     data_offset, db_file);

  thd->pop_internal_handler();

  if (error)
  {
    my_free(screen_buff);
    if (! pack_header_error_handler.is_handled())
      DBUG_RETURN(1);

    // Try again without UNIREG screens (to get more columns)
    if (!(screen_buff=pack_screens(create_fields,&info_length,&screens,1)))
      DBUG_RETURN(1);
    if (pack_header(forminfo, ha_legacy_type(create_info->db_type),
                    create_fields,info_length,
		    screens, create_info->table_options, data_offset, db_file))
    {
      my_free(screen_buff);
      DBUG_RETURN(1);
    }
  }
  reclength=uint2korr(forminfo+266);

  /* Calculate extra data segment length */
  str_db_type.str= (char *) ha_resolve_storage_engine_name(create_info->db_type);
  str_db_type.length= strlen(str_db_type.str);
  /* str_db_type */
  create_info->extra_size= (2 + str_db_type.length +
                            2 + create_info->connect_string.length);
  /*
    Partition:
      Length of partition info = 4 byte
      Potential NULL byte at end of partition info string = 1 byte
      Indicator if auto-partitioned table = 1 byte
      => Total 6 byte
  */
  create_info->extra_size+= 6;
  if (part_info)
  {
    create_info->extra_size+= part_info->part_info_len;
  }

  for (i= 0; i < keys; i++)
  {
    if (key_info[i].parser_name)
      create_info->extra_size+= key_info[i].parser_name->length + 1;
  }
  /*
    This gives us the byte-position of the character at
    (character-position, not byte-position) TABLE_COMMENT_MAXLEN.
    The trick here is that character-positions start at 0, so the last
    character in a maximum-allowed length string would be at char-pos
    MAXLEN-1; charpos MAXLEN will be the position of the terminator.
    Consequently, bytepos(charpos(MAXLEN)) should be equal to
    comment[length] (which should also be the terminator, or at least
    the first byte after the payload in the strict sense). If this is
    not so (bytepos(charpos(MAXLEN)) comes /before/ the end of the
    string), the string is too long.

    For additional credit, realise that UTF-8 has 1-3 bytes before 6.0,
    and 1-4 bytes in 6.0 (6.0 also has UTF-32).
  */
  if (create_info->comment.length > TABLE_COMMENT_MAXLEN)
  {
    const char *real_table_name= table;
    List_iterator<Create_field> it(create_fields);
    Create_field *field;
    while ((field=it++))
    {
      if (field->field && field->field->table &&
        (real_table_name= field->field->table->s->table_name.str))
         break;
    }
    if (validate_comment_length(thd,
                                create_info->comment.str,
                                &create_info->comment.length,
                                TABLE_COMMENT_MAXLEN,
                                ER_TOO_LONG_TABLE_COMMENT,
                                real_table_name))
    {
      my_free(screen_buff);
      DBUG_RETURN(true);
    }
  }
  /*
    If table comment is longer than TABLE_COMMENT_INLINE_MAXLEN bytes,
    store the comment in an extra segment (up to TABLE_COMMENT_MAXLEN bytes).
    Pre 6.0, the limit was 60 characters, with no extra segment-handling.
  */
  if (create_info->comment.length > TABLE_COMMENT_INLINE_MAXLEN)
  {
    forminfo[46]=255;
    create_info->extra_size+= 2 + create_info->comment.length;
  }
  else{
    strmake((char*) forminfo+47, create_info->comment.str ?
            create_info->comment.str : "", create_info->comment.length);
    forminfo[46]=(uchar) create_info->comment.length;
  }

  /*
    Add room in extra segment for "format section" with additional
    table and column properties
  */
  if (create_info->tablespace)
  {
    tablespace_length= strlen(create_info->tablespace);
    /*
      Make sure we have at least an IX lock on the tablespace name,
      unless this is a temporary table. For temporary tables, the
      tablespace name is not IX locked.
    */
    if (tablespace_length > 0 &&
        !(create_info->options & HA_LEX_CREATE_TMP_TABLE))
      DBUG_ASSERT(thd->mdl_context.owns_equal_or_stronger_lock(
                                     MDL_key::TABLESPACE, "",
                                     create_info->tablespace,
                                     MDL_INTENTION_EXCLUSIVE));
  }
  format_section_length=
    format_section_header_size +
    tablespace_length + 1 +
    create_fields.elements;
  create_info->extra_size+= format_section_length;

  create_info->extra_size+= 2 + create_info->compress.length;

  create_info->extra_size+= 2 + create_info->encrypt_type.length;

  if ((file=create_frm(thd, file_name, db, table, reclength, fileinfo,
		       create_info, keys, key_info)) < 0)
  {
    my_free(screen_buff);
    DBUG_RETURN(1);
  }

  key_buff_length= uint4korr(fileinfo+47);
  keybuff=(uchar*) my_malloc(key_memory_frm,
                             key_buff_length, MYF(0));
  key_info_length= pack_keys(keybuff, keys, key_info, data_offset);

  /*
    Ensure that there are no forms in this newly created form file.
    Even if the form file exists, create_frm must truncate it to
    ensure one form per form file.
  */
  DBUG_ASSERT(uint2korr(fileinfo+8) == 0);

  if (!(filepos= make_new_entry(file, fileinfo, NULL, "")))
    goto err;
  maxlength=(uint) next_io_size((ulong) (uint2korr(forminfo_p)+1000));
  int2store(forminfo+2,maxlength);
  int4store(fileinfo+10,(ulong) (filepos+maxlength));
  fileinfo[26]= (uchar) MY_TEST((create_info->max_rows == 1) &&
                                (create_info->min_rows == 1) && (keys == 0));
  int2store(fileinfo+28,key_info_length);

  if (part_info)
  {
    fileinfo[61]= (uchar) ha_legacy_type(part_info->default_engine_type);
    DBUG_PRINT("info", ("part_db_type = %d", fileinfo[61]));
  }
  int2store(fileinfo+59,db_file->extra_rec_buf_length());

  if (mysql_file_pwrite(file, fileinfo, 64, 0L, MYF_RW) ||
      mysql_file_pwrite(file, keybuff, key_info_length,
                        (ulong) uint2korr(fileinfo+6), MYF_RW))
    goto err;
  mysql_file_seek(file,
                  (ulong) uint2korr(fileinfo+6) + (ulong) key_buff_length,
                  MY_SEEK_SET, MYF(0));
  if (make_empty_rec(thd,file,
                     create_info->table_options,
		     create_fields,reclength, data_offset, db_file))
    goto err;

  int2store(buff, static_cast<uint16>(create_info->connect_string.length));
  if (mysql_file_write(file, (const uchar*)buff, 2, MYF(MY_NABP)) ||
      mysql_file_write(file, (const uchar*)create_info->connect_string.str,
               create_info->connect_string.length, MYF(MY_NABP)))
      goto err;

  int2store(buff, static_cast<uint16>(str_db_type.length));
  if (mysql_file_write(file, (const uchar*)buff, 2, MYF(MY_NABP)) ||
      mysql_file_write(file, (const uchar*)str_db_type.str,
               str_db_type.length, MYF(MY_NABP)))
    goto err;

  if (part_info)
  {
    char auto_partitioned= part_info->is_auto_partitioned ? 1 : 0;
    int4store(buff, static_cast<uint32>(part_info->part_info_len));
    if (mysql_file_write(file, (const uchar*)buff, 4, MYF_RW) ||
        mysql_file_write(file, (const uchar*)part_info->part_info_string,
                 part_info->part_info_len + 1, MYF_RW) ||
        mysql_file_write(file, (const uchar*)&auto_partitioned, 1, MYF_RW))
      goto err;
  }
  else
  {
    memset(buff, 0, 6);
    if (mysql_file_write(file, (uchar*) buff, 6, MYF_RW))
      goto err;
  }
  for (i= 0; i < keys; i++)
  {
    if (key_info[i].parser_name)
    {
      if (mysql_file_write(file, (const uchar*)key_info[i].parser_name->str,
                           key_info[i].parser_name->length + 1, MYF(MY_NABP)))
        goto err;
    }
  }
  if (forminfo[46] == (uchar)255)
  {
    uchar comment_length_buff[2];
    int2store(comment_length_buff, static_cast<uint16>(create_info->comment.length));
    if (mysql_file_write(file, comment_length_buff, 2, MYF(MY_NABP)) ||
        mysql_file_write(file, (uchar*) create_info->comment.str,
                         create_info->comment.length, MYF(MY_NABP)))
      goto err;
  }

  /* "Format section" with additional table and column properties */
  {
    uchar *ptr, *format_section_buff;
    if (!(format_section_buff=(uchar*) my_malloc(key_memory_frm,
                                                 format_section_length,
                                                 MYF(MY_WME))))
      goto err;
    ptr= format_section_buff;

    /* header */
    const uint format_section_flags=
      create_info->storage_media; // 3 bits
    const uint format_section_unused= 0;
    int2store(ptr+0, format_section_length);
    int4store(ptr+2, format_section_flags);
    int2store(ptr+6, format_section_unused);
    ptr+= format_section_header_size;

    /* tablespace name */
    if (tablespace_length > 0)
      memcpy(ptr, create_info->tablespace, tablespace_length);
    ptr+= tablespace_length;
    *ptr= 0; /* tablespace string terminating zero */
    ptr++;

    /* column properties  */
    Create_field *field;
    List_iterator<Create_field> it(create_fields);
    while ((field=it++))
    {
      const uchar field_storage= field->field_storage_type();
      const uchar field_column_format= field->column_format();
      const uchar field_flags=
        field_storage + (field_column_format << COLUMN_FORMAT_SHIFT);
      *ptr= field_flags;
      ptr++;
    }
    DBUG_ASSERT(format_section_buff + format_section_length == ptr);

    if (mysql_file_write(file, format_section_buff,
                         format_section_length, MYF_RW))
    {
      my_free(format_section_buff);
      goto err;
    }
    DBUG_PRINT("info", ("wrote format section, length: %u",
                        format_section_length));
    my_free(format_section_buff);
  }

  /* Write out the COMPRESS table attribute */
  {
    uchar length_buff[2];

    int2store(length_buff, static_cast<uint16>(create_info->compress.length));

    if (mysql_file_write(file, length_buff, 2, MYF(MY_NABP)) ||
        mysql_file_write(file, (uchar*) create_info->compress.str,
                         create_info->compress.length, MYF(MY_NABP)))
      goto err;
  }

  /* Write out the ENCRYPT table attribute */
  {
    uchar length_buff[2];

    int2store(length_buff,
	      static_cast<uint16>(create_info->encrypt_type.length));

    if (mysql_file_write(file, length_buff, 2, MYF(MY_NABP)) ||
        mysql_file_write(file, (uchar*) create_info->encrypt_type.str,
                         create_info->encrypt_type.length, MYF(MY_NABP)))
      goto err;
  }

  mysql_file_seek(file, filepos, MY_SEEK_SET, MYF(0));
  if (mysql_file_write(file, forminfo, 288, MYF_RW) ||
      mysql_file_write(file, screen_buff, info_length, MYF_RW) ||
      pack_fields(file, create_fields, data_offset))
    goto err;

  my_free(screen_buff);
  my_free(keybuff);

  if (opt_sync_frm && !(create_info->options & HA_LEX_CREATE_TMP_TABLE) &&
      (mysql_file_sync(file, MYF(MY_WME)) ||
       my_sync_dir_by_file(file_name, MYF(MY_WME))))
      goto err2;

  if (mysql_file_close(file, MYF(MY_WME)))
    goto err3;

  {
    /* 
      Restore all UCS2 intervals.
      HEX representation of them is not needed anymore.
    */
    List_iterator<Create_field> it(create_fields);
    Create_field *field;
    while ((field=it++))
    {
      if (field->save_interval)
      {
        field->interval= field->save_interval;
        field->save_interval= 0;
      }
    }
  }
  DBUG_RETURN(0);

err:
  my_free(screen_buff);
  my_free(keybuff);
err2:
  (void) mysql_file_close(file, MYF(MY_WME));
err3:
  mysql_file_delete(key_file_frm, file_name, MYF(0));
  DBUG_RETURN(1);
} /* mysql_create_frm */


/**
  Create a frm (table definition) file and the tables

  @param thd           Thread handler
  @param path          Name of file (including database, without .frm)
  @param db            Data base name
  @param table_name    Table name
  @param create_info   create info parameters
  @param create_fields Fields to create
  @param keys          number of keys to create
  @param key_info      Keys to create
  @param file          Handler to use
  @param no_ha_table   Indicates that only .FRM file (and PAR file if table
                       is partitioned) needs to be created and not a table
                       in the storage engine.

  @retval 0   ok
  @retval 1   error
*/

int rea_create_table(THD *thd, const char *path,
                     const char *db, const char *table_name,
                     HA_CREATE_INFO *create_info,
                     List<Create_field> &create_fields,
                     uint keys, KEY *key_info, handler *file,
                     bool no_ha_table)
{
  DBUG_ENTER("rea_create_table");

  char frm_name[FN_REFLEN + 1];
  strxnmov(frm_name, sizeof(frm_name) - 1, path, reg_ext, NullS);

  if (mysql_create_frm(thd, frm_name, db, table_name, create_info,
                       create_fields, keys, key_info, file))

    DBUG_RETURN(1);

  // Make sure mysql_create_frm din't remove extension
  DBUG_ASSERT(*fn_rext(frm_name));
  if (thd->variables.keep_files_on_create)
    create_info->options|= HA_CREATE_KEEP_FILES;

  if (file->ha_create_handler_files(path, NULL, CHF_CREATE_FLAG,
                                    create_info))
    goto err_handler_frm;

  if (!no_ha_table &&
       ha_create_table(thd, path, db, table_name, create_info, 0))
    goto err_handler;
  DBUG_RETURN(0);

err_handler:
  (void) file->ha_create_handler_files(path, NULL, CHF_DELETE_FLAG, create_info);

err_handler_frm:
  mysql_file_delete(key_file_frm, frm_name, MYF(0));
  DBUG_RETURN(1);
} /* rea_create_table */


	/* Pack screens to a screen for save in a form-file */

static uchar *pack_screens(List<Create_field> &create_fields,
                           uint *info_length, uint *screens,
                           bool small_file)
{
  uint i;
  uint row,start_row,end_row,fields_on_screen;
  size_t length;
  uint cols;
  uchar *info,*pos,*start_screen;
  uint fields=create_fields.elements;
  List_iterator<Create_field> it(create_fields);
  DBUG_ENTER("pack_screens");

  start_row=4; end_row=22; cols=80; fields_on_screen=end_row+1-start_row;

  *screens=(fields-1)/fields_on_screen+1;
  length= (*screens) * (SC_INFO_LENGTH+ (cols>> 1)+4);

  Create_field *field;
  while ((field=it++))
    length+= strlen(field->field_name)+1+TE_INFO_LENGTH+cols/2;

  if (!(info=(uchar*) my_malloc(key_memory_frm,
                                length,MYF(MY_WME))))
    DBUG_RETURN(0);

  start_screen=0;
  row=end_row;
  pos=info;
  it.rewind();
  for (i=0 ; i < fields ; i++)
  {
    Create_field *cfield=it++;
    if (row++ == end_row)
    {
      if (i)
      {
	length=(uint) (pos-start_screen);
	int2store(start_screen, static_cast<uint16>(length));
	start_screen[2]=(uchar) (fields_on_screen+1);
	start_screen[3]=(uchar) (fields_on_screen);
      }
      row=start_row;
      start_screen=pos;
      pos+=4;
      pos[0]= (uchar) start_row-2;	/* Header string */
      pos[1]= (uchar) (cols >> 2);
      pos[2]= (uchar) (cols >> 1) +1;
      strfill((char *) pos+3,(uint) (cols >> 1),' ');
      pos+=(cols >> 1)+4;
    }
    length= strlen(cfield->field_name);
    if (length > cols-3)
      length=cols-3;

    if (!small_file)
    {
      pos[0]=(uchar) row;
      pos[1]=0;
      pos[2]=(uchar) (length+1);
      pos=(uchar*) strmake((char*) pos+3,cfield->field_name,length)+1;
    }
    cfield->row=(uint8) row;
    cfield->col=(uint8) (length+1);
    cfield->sc_length= min<uint8>(cfield->length, cols - (length + 2));
  }
  length=(uint) (pos-start_screen);
  int2store(start_screen, static_cast<uint16>(length));
  start_screen[2]=(uchar) (row-start_row+2);
  start_screen[3]=(uchar) (row-start_row+1);

  *info_length=(uint) (pos-info);
  DBUG_RETURN(info);
} /* pack_screens */


	/* Pack keyinfo and keynames to keybuff for save in form-file. */

static uint pack_keys(uchar *keybuff, uint key_count, KEY *keyinfo,
                      ulong data_offset)
{
  uint key_parts,length;
  uchar *pos, *keyname_pos;
  KEY *key,*end;
  KEY_PART_INFO *key_part,*key_part_end;
  DBUG_ENTER("pack_keys");

  pos=keybuff+6;
  key_parts=0;
  for (key=keyinfo,end=keyinfo+key_count ; key != end ; key++)
  {
    int2store(pos, static_cast<uint16>(key->flags ^ HA_NOSAME));
    int2store(pos+2,key->key_length);
    pos[4]= (uchar) key->user_defined_key_parts;
    pos[5]= (uchar) key->algorithm;
    int2store(pos+6, key->block_size);
    pos+=8;
    key_parts+=key->user_defined_key_parts;
    DBUG_PRINT("loop", ("flags: %lu  key_parts: %d at 0x%lx",
                        key->flags, key->user_defined_key_parts,
                        (long) key->key_part));
    for (key_part=key->key_part,
           key_part_end= key_part + key->user_defined_key_parts ;
	 key_part != key_part_end ;
	 key_part++)

    {
      uint offset;
      DBUG_PRINT("loop",("field: %d  startpos: %lu  length: %d",
			 key_part->fieldnr, key_part->offset + data_offset,
                         key_part->length));
      int2store(pos,key_part->fieldnr+1+FIELD_NAME_USED);
      offset= (uint) (key_part->offset+data_offset+1);
      int2store(pos+2, offset);
      pos[4]=0;					// Sort order
      int2store(pos+5,key_part->key_type);
      int2store(pos+7,key_part->length);
      pos+=9;
    }
  }
	/* Save keynames */
  keyname_pos=pos;
  *pos++=(uchar) NAMES_SEP_CHAR;
  for (key=keyinfo ; key != end ; key++)
  {
    uchar *tmp=(uchar*) my_stpcpy((char*) pos,key->name);
    *tmp++= (uchar) NAMES_SEP_CHAR;
    *tmp=0;
    pos=tmp;
  }
  *(pos++)=0;
  for (key=keyinfo,end=keyinfo+key_count ; key != end ; key++)
  {
    if (key->flags & HA_USES_COMMENT)
    {
      int2store(pos, static_cast<uint16>(key->comment.length));
      uchar *tmp= (uchar*)my_stpnmov((char*) pos+2,key->comment.str,
                                     key->comment.length);
      pos= tmp;
    }
  }

  if (key_count > 127 || key_parts > 127)
  {
    keybuff[0]= (key_count & 0x7f) | 0x80;
    keybuff[1]= key_count >> 7;
    int2store(keybuff+2,key_parts);
  }
  else
  {
    keybuff[0]=(uchar) key_count;
    keybuff[1]=(uchar) key_parts;
    keybuff[2]= keybuff[3]= 0;
  }
  length=(uint) (pos-keyname_pos);
  int2store(keybuff+4,length);
  DBUG_RETURN((uint) (pos-keybuff));
} /* pack_keys */


	/* Make formheader */

static bool pack_header(uchar *forminfo, enum legacy_db_type table_type,
			List<Create_field> &create_fields,
                        uint info_length, uint screens, uint table_options,
                        ulong data_offset, handler *file)
{
  size_t length;
  uint int_count, int_length, no_empty, int_parts;
  uint time_stamp_pos,null_fields;
  size_t reclength, totlength, n_length, com_length, gcol_info_length;
  DBUG_ENTER("pack_header");

  if (create_fields.elements > MAX_FIELDS)
  {
    my_message(ER_TOO_MANY_FIELDS, ER(ER_TOO_MANY_FIELDS), MYF(0));
    DBUG_RETURN(1);
  }

  totlength= 0L;
  reclength= data_offset;
  no_empty=int_count=int_parts=int_length=time_stamp_pos=null_fields=0;
  com_length=gcol_info_length=0;
  n_length=2L;

	/* Check fields */

  List_iterator<Create_field> it(create_fields);
  Create_field *field;
  while ((field=it++))
  {
    THD *thd= current_thd;

    if (validate_comment_length(thd,
                                field->comment.str,
                                &field->comment.length,
                                COLUMN_COMMENT_MAXLEN,
                                ER_TOO_LONG_FIELD_COMMENT,
                                (char *) field->field_name))
      DBUG_RETURN(true);
    if (field->gcol_info)
    {
      sql_mode_t sql_mode= thd->variables.sql_mode;
      thd->variables.sql_mode&= ~MODE_ANSI_QUOTES;

      /*
        It is important to normalize the expression's text into the FRM, to
        make it independent from sql_mode. For example, 'a||b' means 'a OR b'
        or 'CONCAT(a,b)', depending on if PIPES_AS_CONCAT is on. Using
        Item::print(), we get self-sufficient text containing 'OR' or
        'CONCAT'. If sql_mode later changes, it will not affect the column.
       */
      String s;
      // Printing db and table name is useless
      field->gcol_info->expr_item->
        print(&s, enum_query_type(QT_NO_DB | QT_NO_TABLE));

      thd->variables.sql_mode= sql_mode;
      /*
        The new text must have exactly the same lifetime as the old text, it's
        a replacement for it. So the same MEM_ROOT must be used: pass NULL.
      */
      field->gcol_info->dup_expr_str(NULL, s.ptr(), s.length());

      uint tmp_len= system_charset_info->cset->charpos(system_charset_info,
                                                       field->gcol_info->expr_str.str,
                                                       field->gcol_info->expr_str.str +
                                                       field->gcol_info->expr_str.length,
                                                       GENERATED_COLUMN_EXPRESSION_MAXLEN);

      if (tmp_len < field->gcol_info->expr_str.length)
      {
        my_error(ER_WRONG_STRING_LENGTH, MYF(0),
                 field->gcol_info->expr_str.str,"GENERATED COLUMN EXPRESSION",
                 (uint) GENERATED_COLUMN_EXPRESSION_MAXLEN);
        DBUG_RETURN(1);
      }
      /*
        Sum up the length of the expression string and mandatory header bytes
        to the total length.
      */
      gcol_info_length+= field->gcol_info->expr_str.length+(uint)FRM_GCOL_HEADER_SIZE;
    }
    totlength+= field->length;
    com_length+= field->comment.length;
    if (MTYP_TYPENR(field->unireg_check) == Field::NOEMPTY ||
	field->unireg_check & MTYP_NOEMPTY_BIT)
    {
      field->unireg_check= (Field::utype) ((uint) field->unireg_check |
					   MTYP_NOEMPTY_BIT);
      no_empty++;
    }
    /* 
      We mark first TIMESTAMP field with NOW() in DEFAULT or ON UPDATE 
      as auto-update field.
    */
    if (field->sql_type == MYSQL_TYPE_TIMESTAMP &&
        MTYP_TYPENR(field->unireg_check) != Field::NONE &&
	!time_stamp_pos)
      time_stamp_pos= (uint) field->offset+ (uint) data_offset + 1;
    length=field->pack_length;
    /* Ensure we don't have any bugs when generating offsets */
    /**
      Because the virtual generated columns are not stored physically,
      they are put at the tail of record. The details can be checked
      in mysql_prepare_create_table. So the offset is messed up by
      vitual generated columns. The original assert is not correct
      any more.
      DBUG_ASSERT(reclength == field->offset + data_offset);
     */
    if (field->offset + data_offset + length > reclength)
      reclength= field->offset + data_offset + length;
    n_length+= strlen(field->field_name) + 1;
    field->interval_id=0;
    field->save_interval= 0;
    if (field->interval)
    {
      uint old_int_count=int_count;

      if (field->charset->mbminlen > 1)
      {
        /* 
          Escape UCS2 intervals using HEX notation to avoid
          problems with delimiters between enum elements.
          As the original representation is still needed in 
          the function make_empty_rec to create a record of
          filled with default values it is saved in save_interval
          The HEX representation is created from this copy.
        */
        field->save_interval= field->interval;
        field->interval= (TYPELIB*) sql_alloc(sizeof(TYPELIB));
        *field->interval= *field->save_interval; 
        field->interval->type_names= 
          (const char **) sql_alloc(sizeof(char*) * 
				    (field->interval->count+1));
        field->interval->type_names[field->interval->count]= 0;
        field->interval->type_lengths=
          (uint *) sql_alloc(sizeof(uint) * field->interval->count);
 
        for (uint pos= 0; pos < field->interval->count; pos++)
        {
          char *dst;
          const char *src= field->save_interval->type_names[pos];
          size_t hex_length;
          length= field->save_interval->type_lengths[pos];
          hex_length= length * 2;
          field->interval->type_lengths[pos]= hex_length;
          field->interval->type_names[pos]= dst= (char*) sql_alloc(hex_length +
                                                                   1);
          octet2hex(dst, src, length);
        }
      }

      field->interval_id=get_interval_id(&int_count,create_fields,field);
      if (old_int_count != int_count)
      {
	for (const char **pos=field->interval->type_names ; *pos ; pos++)
	  int_length+=(uint) strlen(*pos)+1;	// field + suffix prefix
	int_parts+=field->interval->count+1;
      }
    }
    if (f_maybe_null(field->pack_flag))
      null_fields++;
  }
  int_length+=int_count*2;			// 255 prefix + 0 suffix

	/* Save values in forminfo */

  if (reclength > (ulong) file->max_record_length())
  {
    my_error(ER_TOO_BIG_ROWSIZE, MYF(0), static_cast<long>(file->max_record_length()));
    DBUG_RETURN(1);
  }
  /* Hack to avoid bugs with small static rows in MySQL */
  reclength= max<size_t>(file->min_record_length(table_options), reclength);
  if (info_length + (ulong) create_fields.elements * FCOMP + 288 +
      n_length + int_length + com_length + gcol_info_length > 65535L ||
      int_count > 255)
  {
    my_message(ER_TOO_MANY_FIELDS, ER(ER_TOO_MANY_FIELDS), MYF(0));
    DBUG_RETURN(1);
  }

  memset(forminfo, 0, 288);
  length=(info_length+create_fields.elements*FCOMP+288+n_length+int_length+
	  com_length + gcol_info_length);
  int2store(forminfo, static_cast<uint16>(length));
  forminfo[256] = (uint8) screens;
  int2store(forminfo+258,create_fields.elements);
  int2store(forminfo+260,info_length);
  int2store(forminfo+262, static_cast<uint16>(totlength));
  int2store(forminfo+264,no_empty);
  int2store(forminfo+266, static_cast<uint16>(reclength));
  int2store(forminfo+268, static_cast<uint16>(n_length));
  int2store(forminfo+270,int_count);
  int2store(forminfo+272,int_parts);
  int2store(forminfo+274,int_length);
  int2store(forminfo+276,time_stamp_pos);
  int2store(forminfo+278,80);			/* Columns needed */
  int2store(forminfo+280,22);			/* Rows needed */
  int2store(forminfo+282,null_fields);
  int2store(forminfo+284, static_cast<uint16>(com_length));
  int2store(forminfo+286,gcol_info_length);
  /* forminfo+288 is free to use for additional information */
  DBUG_RETURN(0);
} /* pack_header */


	/* get each unique interval each own id */

static uint get_interval_id(uint *int_count,List<Create_field> &create_fields,
			    Create_field *last_field)
{
  List_iterator<Create_field> it(create_fields);
  Create_field *field;
  TYPELIB *interval=last_field->interval;

  while ((field=it++) != last_field)
  {
    if (field->interval_id && field->interval->count == interval->count)
    {
      const char **a,**b;
      for (a=field->interval->type_names, b=interval->type_names ;
	   *a && !strcmp(*a,*b);
	   a++,b++) ;

      if (! *a)
      {
	return field->interval_id;		// Re-use last interval
      }
    }
  }
  return ++*int_count;				// New unique interval
}


	/* Save fields, fieldnames and intervals */

static bool pack_fields(File file, List<Create_field> &create_fields,
                        ulong data_offset)
{
  uint i;
  uint int_count, gcol_info_length=0;
  size_t comment_length= 0;
  uchar buff[MAX_FIELD_WIDTH];
  Create_field *field;
  DBUG_ENTER("pack_fields");

	/* Write field info */

  List_iterator<Create_field> it(create_fields);

  int_count=0;
  while ((field=it++))
  {
    uint recpos;
    buff[0]= (uchar) field->row;
    buff[1]= (uchar) field->col;
    buff[2]= (uchar) field->sc_length;
    int2store(buff+3, static_cast<uint16>(field->length));
    /* The +1 is here becasue the col offset in .frm file have offset 1 */
    recpos= field->offset+1 + (uint) data_offset;
    int3store(buff+5,recpos);
    int2store(buff+8,field->pack_flag);
    buff[10]= (uchar) field->unireg_check;
    buff[12]= (uchar) field->interval_id;
    buff[13]= (uchar) field->sql_type; 
    if (field->sql_type == MYSQL_TYPE_GEOMETRY)
    {
      buff[11]= 0;
      buff[14]= (uchar) field->geom_type;
    }
    else if (field->charset) 
    {
      buff[11]= (uchar) (field->charset->number >> 8);
      buff[14]= (uchar) field->charset->number;
    }
    else
    {
      buff[11]= buff[14]= 0;			// Numerical
    }
    if (field->gcol_info)
    {
      gcol_info_length+= field->gcol_info->expr_str.length;
      buff[10]|= (uchar)Field::GENERATED_FIELD;
    }
    int2store(buff+15, static_cast<uint16>(field->comment.length));
    comment_length+= field->comment.length;
    set_if_bigger(int_count,field->interval_id);
    if (mysql_file_write(file, buff, FCOMP, MYF_RW))
      DBUG_RETURN(1);
  }

	/* Write fieldnames */
  buff[0]=(uchar) NAMES_SEP_CHAR;
  if (mysql_file_write(file, buff, 1, MYF_RW))
    DBUG_RETURN(1);
  i=0;
  it.rewind();
  while ((field=it++))
  {
    char *pos= my_stpcpy((char*) buff,field->field_name);
    *pos++=NAMES_SEP_CHAR;
    if (i == create_fields.elements-1)
      *pos++=0;
    if (mysql_file_write(file, buff, (size_t) (pos-(char*) buff), MYF_RW))
      DBUG_RETURN(1);
    i++;
  }

	/* Write intervals */
  if (int_count)
  {
    String tmp((char*) buff,sizeof(buff), &my_charset_bin);
    tmp.length(0);
    it.rewind();
    int_count=0;
    while ((field=it++))
    {
      if (field->interval_id > int_count)
      {
        unsigned char  sep= 0;
        unsigned char  occ[256];
        uint           i;
        unsigned char *val= NULL;

        memset(occ, 0, sizeof(occ));

        for (i=0; (val= (unsigned char*) field->interval->type_names[i]); i++)
          for (uint j = 0; j < field->interval->type_lengths[i]; j++)
            occ[(unsigned int) (val[j])]= 1;

        if (!occ[(unsigned char)NAMES_SEP_CHAR])
          sep= (unsigned char) NAMES_SEP_CHAR;
        else if (!occ[(unsigned int)','])
          sep= ',';
        else
        {
          for (uint i=1; i<256; i++)
          {
            if(!occ[i])
            {
              sep= i;
              break;
            }
          }

          if(!sep)    /* disaster, enum uses all characters, none left as separator */
          {
            my_message(ER_WRONG_FIELD_TERMINATORS,ER(ER_WRONG_FIELD_TERMINATORS),
                       MYF(0));
            DBUG_RETURN(1);
          }
        }

        int_count= field->interval_id;
        tmp.append(sep);
        for (const char **pos=field->interval->type_names ; *pos ; pos++)
        {
          tmp.append(*pos);
          tmp.append(sep);
        }
        tmp.append('\0');                      // End of intervall
      }
    }
    if (mysql_file_write(file, (uchar*) tmp.ptr(), tmp.length(), MYF_RW))
      DBUG_RETURN(1);
  }
  if (comment_length)
  {
    it.rewind();
    int_count=0;
    while ((field=it++))
    {
      if (field->comment.length)
        if (mysql_file_write(file, (uchar*) field->comment.str,
                             field->comment.length, MYF_RW))
	  DBUG_RETURN(1);
    }
  }
  if (gcol_info_length)
  {
    it.rewind();
    int_count=0;
    while ((field=it++))
    {
      /*
        Pack each virtual field as follows:
        byte 1      = 1 (always 1 to allow for future extensions)
        byte 2,3    = expression length
        byte 4      = flags, as of now:
                        0 - no flags
                        1 - field is physically stored
        byte 5-...  = generated column expression (text data)
      */
      if (field->gcol_info && field->gcol_info->expr_str.length)
      {
        buff[0]= (uchar)1;
        int2store(buff + 1, field->gcol_info->expr_str.length);
        buff[3]= (uchar) field->stored_in_db;
        if (my_write(file, buff, FRM_GCOL_HEADER_SIZE, MYF_RW))
          DBUG_RETURN(1);
        if (my_write(file,
                     (uchar*) field->gcol_info->expr_str.str,
                     field->gcol_info->expr_str.length,
                     MYF_RW))
          DBUG_RETURN(1);
      }
    }
  }
  DBUG_RETURN(0);
}


/**
  Auxiliary function which stores field's explicit or implicit default
  value in record buffer.

  @param         thd         Connection's context.
  @param         table       Table for which field default value to be stored.
  @param         field       Field definition object.
  @param         rec_pos     Pointer to the main part of record buffer where
                             field values are stored (as opposed to record
                             preamble).
  @param         null_pos    Pointer to the preamble part of record buffer
                             where null bits and leftover bits from BIT fields
                             are stored.
  @param[in/out] null_count  Index of bit in preamble to be used for storing
                             NULL/leftover bits for the field if necessary. On
                             return incremented by number of bits in preamble
                             used for this field.

  @retval true  An error occured.
  @retval false Success.
*/

bool make_default_value(THD *thd, TABLE *table, Create_field *field,
                        uchar *rec_pos, uchar *null_pos, uint *null_count)
{
  Field *regfield= make_field(table->s,
                              rec_pos + field->offset,
                              field->length,
                              null_pos + *null_count / 8,
                              *null_count & 7,
                              field->pack_flag,
                              field->sql_type,
                              field->charset,
                              field->geom_type,
                              field->unireg_check,
                              field->save_interval ? field->save_interval :
                              field->interval,
                              field->field_name);
  if (!regfield)
    return true;   // End of memory

  /* save_in_field() will access regfield->table->in_use */
  regfield->init(table);

  if (!(field->flags & NOT_NULL_FLAG))
  {
    regfield->set_null();
    (*null_count)++;
  }

  if (field->sql_type == MYSQL_TYPE_BIT && !f_bit_as_char(field->pack_flag))
    (*null_count)+= field->length & 7;

  Field::utype type= (Field::utype) MTYP_TYPENR(field->unireg_check);

  if (field->def)
  {
    /*
      Storing the value of a function is pointless as this function may not
      be constant.
    */
    DBUG_ASSERT(field->def->type() != Item::FUNC_ITEM);
    type_conversion_status res= field->def->save_in_field(regfield, true);
    if (res != TYPE_OK && res != TYPE_NOTE_TIME_TRUNCATED &&
        res != TYPE_NOTE_TRUNCATED)
    {
      /*
        clear current error and report INVALID DEFAULT value error message
      */
      if (thd->is_error())
        thd->clear_error();

      my_error(ER_INVALID_DEFAULT, MYF(0), regfield->field_name);
      /*
        Delete to avoid memory leak for fields that allocate extra
        memory (e.g Field_blob::value)
      */
      delete regfield;
      return true;
    }
  }
  else if (regfield->real_type() == MYSQL_TYPE_ENUM &&
           (field->flags & NOT_NULL_FLAG))
  {
    regfield->set_notnull();
    regfield->store((longlong) 1, TRUE);
  }
  else if (type == Field::YES)		// Old unireg type
    regfield->store(ER(ER_YES), strlen(ER(ER_YES)),system_charset_info);
  else if (type == Field::NO)			// Old unireg type
    regfield->store(ER(ER_NO), strlen(ER(ER_NO)),system_charset_info);
  else
    regfield->reset();
  /*
    Delete to avoid memory leak for fields that allocate extra
    memory (e.g Field_blob::value)
  */
  delete regfield;
  return false;
}


/**
   Creates a record buffer consisting of default values for all columns and
   stores it in the formfile (.frm file.)

   The value stored for each column is

   - The default value if the column has one.
   - 1 if the column type is @c enum.
   - Special messages if the unireg type is YES or NO.
   - A buffer full of only zeroes in all other cases. This also happens if the
     default is a function.

   @param thd           The current session.
   @param file          The .frm file.
   @param table_options Describes how to pack the values in the buffer.
   @param create_fields A list of column definition objects.
   @param reclength     Length of the record buffer in bytes.
   @param data_offset   Offset inside the buffer before the values.
   @param handler       The storage engine.

   @retval true An error occured.
   @retval false Success.

*/

static bool make_empty_rec(THD *thd, File file,
			   uint table_options,
			   List<Create_field> &create_fields,
			   uint reclength,
                           ulong data_offset,
                           handler *handler)
{
  int error= 0;
  uint null_count;
  uchar *buff,*null_pos;
  TABLE table;
  TABLE_SHARE share;
  Create_field *field;
  enum_check_fields old_count_cuted_fields= thd->count_cuted_fields;
  bool has_vgc= false;
  DBUG_ENTER("make_empty_rec");

  /* We need a table to generate columns for default values */
  memset(&table, 0, sizeof(table));
  memset(&share, 0, sizeof(share));
  table.s= &share;

  if (!(buff=(uchar*) my_malloc(key_memory_frm,
                                (size_t) reclength,MYF(MY_WME | MY_ZEROFILL))))
  {
    DBUG_RETURN(1);
  }

  table.in_use= thd;
  table.s->db_low_byte_first= handler->low_byte_first();

  null_count=0;
  if (!(table_options & HA_OPTION_PACK_RECORD))
  {
    null_count++;			// Need one bit for delete mark
    *buff|= 1;
  }
  null_pos= buff;

  List_iterator<Create_field> it(create_fields);
  thd->count_cuted_fields= CHECK_FIELD_WARN;    // To find wrong default values
  while ((field=it++))
  {
    if (field->stored_in_db)
    {
      /*
        Even though Create_field::offset for virtual generated columns already
        point at the end of record buffer we still need separate pass for them
        in order to allocate null bits from preamble tail as well.
      */
      if (make_default_value(thd, &table, field, buff + data_offset,
                             null_pos, &null_count))
      {
        error= 1;
        goto err;
      }
    }
    else
      has_vgc= true;
  }
  if (has_vgc)
  {
    it.rewind();
    while ((field=it++))
    {
      if (!field->stored_in_db)
      {
        if (make_default_value(thd, &table, field, buff + data_offset,
                               null_pos, &null_count))
        {
          error= 1;
          goto err;
        }
      }
    }
  }
  DBUG_ASSERT(data_offset == ((null_count + 7) / 8));

  /*
    We need to set the unused bits to 1. If the number of bits is a multiple
    of 8 there are no unused bits.
  */
  if (null_count & 7)
    *(null_pos + null_count / 8)|= ~(((uchar) 1 << (null_count & 7)) - 1);

  error= mysql_file_write(file, buff, (size_t) reclength, MYF_RW) != 0;

err:
  my_free(buff);
  thd->count_cuted_fields= old_count_cuted_fields;
  DBUG_RETURN(error);
} /* make_empty_rec */
