/* 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 */


/* This file defines all string functions
** Warning: Some string functions doesn't always put and end-null on a String
** (This shouldn't be needed)
*/

#ifdef __GNUC__
#pragma implementation				// gcc: Class implementation
#endif

#include "mysql_priv.h"
#include "sql_acl.h"
#include <m_ctype.h>
#ifdef HAVE_CRYPT_H
#include <crypt.h>
#endif
#ifdef HAVE_OPENSSL
#include <openssl/des.h>
#endif /* HAVE_OPENSSL */
#include "md5.h"

String empty_string("");

uint nr_of_decimals(const char *str)
{
  if ((str=strchr(str,'.')))
  {
    const char *start= ++str;
    for ( ; isdigit(*str) ; str++) ;
    return (uint) (str-start);
  }
  return 0;
}

double Item_str_func::val()
{
  String *res;
  res=val_str(&str_value);
  return res ? atof(res->c_ptr()) : 0.0;
}

longlong Item_str_func::val_int()
{
  String *res;
  res=val_str(&str_value);
  return res ? strtoll(res->c_ptr(),NULL,10) : (longlong) 0;
}


String *Item_func_md5::val_str(String *str)
{
  String * sptr= args[0]->val_str(str);
  if (sptr)
  {
    my_MD5_CTX context;
    unsigned char digest[16];

    null_value=0;
    my_MD5Init (&context);
    my_MD5Update (&context,(unsigned char *) sptr->ptr(), sptr->length());
    my_MD5Final (digest, &context);
    str->alloc(32);				// Ensure that memory is free
    sprintf((char *) str->ptr(),
	    "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
	    digest[0], digest[1], digest[2], digest[3],
	    digest[4], digest[5], digest[6], digest[7],
	    digest[8], digest[9], digest[10], digest[11],
	    digest[12], digest[13], digest[14], digest[15]);
    str->length((uint) 32);
    return str;
  }
  null_value=1;
  return 0;
}


void Item_func_md5::fix_length_and_dec()
{
   max_length=32;
}

/*
** Concatinate args with the following premissess
** If only one arg which is ok, return value of arg
** Don't reallocate val_str() if not absolute necessary.
*/

String *Item_func_concat::val_str(String *str)
{
  String *res,*res2,*use_as_buff;
  uint i;

  null_value=0;
  if (!(res=args[0]->val_str(str)))
    goto null;
  use_as_buff= &tmp_value;
  for (i=1 ; i < arg_count ; i++)
  {
    if (res->length() == 0)
    {
      if (!(res=args[i]->val_str(str)))
	goto null;
    }
    else
    {
      if (!(res2=args[i]->val_str(use_as_buff)))
	goto null;
      if (res2->length() == 0)
	continue;
      if (res->length()+res2->length() > max_allowed_packet)
	goto null;				// Error check
      if (res->alloced_length() >= res->length()+res2->length())
      {						// Use old buffer
	res->append(*res2);
      }
      else if (str->alloced_length() >= res->length()+res2->length())
      {
	if (str == res2)
	  str->replace(0,0,*res);
	else
	{
	  str->copy(*res);
	  str->append(*res2);
	}
	res=str;
      }
      else if (res == &tmp_value)
      {
	if (res->append(*res2))			// Must be a blob
	  goto null;
      }
      else if (res2 == &tmp_value)
      {						// This can happend only 1 time
	if (tmp_value.replace(0,0,*res))
	  goto null;
	res= &tmp_value;
	use_as_buff=str;			// Put next arg here
      }
      else if (tmp_value.is_alloced() && res2->ptr() >= tmp_value.ptr() &&
	       res2->ptr() <= tmp_value.ptr() + tmp_value.alloced_length())
      {
	/*
	  This happens really seldom:
	  In this case res2 is sub string of tmp_value.  We will
	  now work in place in tmp_value to set it to res | res2
	*/
	/* Chop the last characters in tmp_value that isn't in res2 */
	tmp_value.length((uint32) (res2->ptr() - tmp_value.ptr()) +
			 res2->length());
	/* Place res2 at start of tmp_value, remove chars before res2 */
	if (tmp_value.replace(0,(uint32) (res2->ptr() - tmp_value.ptr()),
			      *res))
	  goto null;
	res= &tmp_value;
	use_as_buff=str;			// Put next arg here
      }
      else
      {						// Two big const strings
	if (tmp_value.alloc(max_length) ||
	    tmp_value.copy(*res) ||
	    tmp_value.append(*res2))
	  goto null;
	res= &tmp_value;
	use_as_buff=str;
      }
    }
  }
  return res;

null:
  null_value=1;
  return 0;
}


void Item_func_concat::fix_length_and_dec()
{
  max_length=0;
  for (uint i=0 ; i < arg_count ; i++)
    max_length+=args[i]->max_length;
  if (max_length > MAX_BLOB_WIDTH)
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
}

#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')
#define ascii_to_bin(c) ((c)<=57 ? (c)-46 : (c)<=90 ? (c)-53 : (c)-59)

/* 
  Function des_encrypt() by tonu@spam.ee
  Works only if compiled with OpenSSL library support. 
  Output always starts with magic char "1" and all
  encrypted output is encoded into ASCII-protected
  container. 
  Original input is returned as output if input string 
  begins with magic "1". Credit card number always begin 
  with 4,5 or 6.
  Encryption result is longer than original by formula:
  new_length=(8-(original_length % 8))*2+1
*/

String *Item_func_des_encrypt::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
#ifdef HAVE_OPENSSL
  des_key_schedule ks1, ks2, ks3;
  des_cblock ivec={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
  struct {
	  des_cblock key1, key2, key3; // 8 bytes each
  } keyblock;

  if ((null_value=args[0]->null_value))
    return 0;
  if (res->length() == 0)
    return &empty_string;
  if(res->c_ptr()[0]!='1') { // Skip encryption if already encrypted
    String *keystr=args[1]->val_str(&tmp_value);
    /* We make good 24-byte (168 bit) key from given plaintext key with MD5 */
    EVP_BytesToKey(EVP_des_ede3_cbc(),EVP_md5(),NULL,
	(uchar *)keystr->c_ptr(),
	(int)keystr->length(),1,(uchar *)&keyblock,ivec);
    des_set_key_unchecked(&keyblock.key1,ks1); // Here we set all 64-bit keys 
    des_set_key_unchecked(&keyblock.key2,ks2); // (56 effective) one by one
    des_set_key_unchecked(&keyblock.key3,ks3);
    /* 
      The problem: DES algorithm requires original data to be in 8-bytes
      chunks. Missing bytes get filled with zeros and result of encryption 
      can be up to 7 bytes longer than original string. When decrypted, 
      we do not know the size of original string :(
      We add one byte with value 0x0..0x7 to original plaintext marking
      change of string length 
    */
    uchar tail=  7-( res->length() %8); // 0..7 marking real offsets 1..8
    for(int i=0 ; i < tail ; ++i) res->append('*');  
    res->append(tail);  		// Write tail length 0..7 to last pos
    str->length(res->length());
    des_ede3_cbc_encrypt(		// Real encryption
 	(const uchar*)(res->c_ptr()), 
	(uchar*)(str->c_ptr()), 
	res->length(), ks1, ks2, ks3, &ivec, TRUE);
    res->set((const char*)"1",(uint)1); 
    for(uint i=0 ; i < str->length() ; ++i) 
    {
      res->append(bin_to_ascii((uchar)str->c_ptr()[i] & 0x3f)); 
      res->append(bin_to_ascii(((uchar)str->c_ptr()[i] >> 5 ) & 0x3f));
    } 
  }
  return res;
#else
  null_value=1;
  return 0;
#endif	/* HAVE_OPENSSL */
}

String *Item_func_des_decrypt::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
#ifdef HAVE_OPENSSL
  des_key_schedule ks1, ks2, ks3;
  des_cblock ivec={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
  struct {
	  des_cblock key1, key2, key3; // 8 bytes each
  } keyblock;


  if ((null_value=args[0]->null_value))
    return 0;
  if (res->length() == 0)
    return &empty_string;
  
  if(res->c_ptr()[0]=='1') // Skip decryption if not encrypted
  {
    str->set((const char*)0,(uint)0); 
    for(uint i=1 ; i < res->length() ; i+=2) 
    {
      str->append((ascii_to_bin(res->c_ptr()[i])) 
		      | (ascii_to_bin(res->c_ptr()[i+1]) << 5 ));
    }
 
    String *keystr=args[1]->val_str(&tmp_value);
    int32 mode=0; 
    if(arg_count == 3 && !args[2]->null_value) 
      mode=args[2]->val_int();
    /* We make good 24-byte (168 bit) key from given plaintext key with MD5 */
    EVP_BytesToKey(EVP_des_ede3_cbc(),EVP_md5(),NULL,
	(uchar *)keystr->c_ptr(),
	(int)keystr->length(),1,(uchar *)&keyblock,ivec);
    des_set_key_unchecked(&keyblock.key1,ks1);	// Here we set all 64-bit keys 
    des_set_key_unchecked(&keyblock.key2,ks2);	// (56 effective) one by one
    des_set_key_unchecked(&keyblock.key3,ks3);
    res->length(str->length());
    des_ede3_cbc_encrypt(			// Real decryption
	(const uchar*)(str->c_ptr()), 
	(uchar*)(res->c_ptr()), 
	str->length(),                 
	ks1, ks2, ks3, &ivec, FALSE);
    uchar tail=(res->c_ptr()[res->length()-1]) & 0x7;
    if((res->length() > ((uint)1+tail)))   	// We should avoid negative length 
	res->length(res->length()-1-tail); 	// (can happen with wrong key)
  }
  return res;
#else
  null_value=1;
  return 0;
#endif	/* HAVE_OPENSSL */
}



/* 
** concat with separator. First arg is the separator
** concat_ws takes at least two arguments.
*/

String *Item_func_concat_ws::val_str(String *str)
{
  char tmp_str_buff[10];
  String tmp_sep_str(tmp_str_buff, sizeof(tmp_str_buff)),
         *sep_str, *res, *res2,*use_as_buff;
  uint i;

  null_value=0;
  if (!(sep_str= separator->val_str(&tmp_sep_str)))
    goto null;

  use_as_buff= &tmp_value;
  str->length(0);				// QQ; Should be removed
  res=str;

  // Skip until non-null and non-empty argument is found.
  // If not, return the empty string
  for (i=0; i < arg_count; i++)
    if ((res= args[i]->val_str(str)) && res->length())
      break;
  if (i ==  arg_count)
    return &empty_string;

  for (i++; i < arg_count ; i++)
  {
    if (!(res2= args[i]->val_str(use_as_buff)) || !res2->length())
      continue;					// Skip NULL and empty string

    if (res->length() + sep_str->length() + res2->length() >
	max_allowed_packet)
      goto null;				// Error check
    if (res->alloced_length() >=
	res->length() + sep_str->length() + res2->length())
    {						// Use old buffer
      res->append(*sep_str);			// res->length() > 0 always
      res->append(*res2);
    }
    else if (str->alloced_length() >=
	     res->length() + sep_str->length() + res2->length())
    {
      /* We have room in str;  We can't get any errors here */
      if (str == res2)
      {						// This is quote uncommon!
	str->replace(0,0,*sep_str);
	str->replace(0,0,*res);
      }
      else
      {
	str->copy(*res);
	str->append(*sep_str);
	str->append(*res2);
      }
      res=str;
      use_as_buff= &tmp_value;
    }
    else if (res == &tmp_value)
    {
      if (res->append(*sep_str) || res->append(*res2))
	goto null; // Must be a blob
    }
    else if (res2 == &tmp_value)
    {						// This can happend only 1 time
      if (tmp_value.replace(0,0,*sep_str) || tmp_value.replace(0,0,*res))
	goto null;
      res= &tmp_value;
      use_as_buff=str;				// Put next arg here
    }
    else if (tmp_value.is_alloced() && res2->ptr() >= tmp_value.ptr() &&
	     res2->ptr() < tmp_value.ptr() + tmp_value.alloced_length())
    {
      /*
	This happens really seldom:
	In this case res2 is sub string of tmp_value.  We will
	now work in place in tmp_value to set it to res | sep_str | res2
      */
      /* Chop the last characters in tmp_value that isn't in res2 */
      tmp_value.length((uint32) (res2->ptr() - tmp_value.ptr()) +
		       res2->length());
      /* Place res2 at start of tmp_value, remove chars before res2 */
      if (tmp_value.replace(0,(uint32) (res2->ptr() - tmp_value.ptr()),
			    *res) ||
	  tmp_value.replace(res->length(),0, *sep_str))
	goto null;
      res= &tmp_value;
      use_as_buff=str;			// Put next arg here
    }
    else
    {						// Two big const strings
      if (tmp_value.alloc(max_length) ||
	  tmp_value.copy(*res) ||
	  tmp_value.append(*sep_str) ||
	  tmp_value.append(*res2))
	goto null;
      res= &tmp_value;
      use_as_buff=str;
    }
  }
  return res;

null:
  null_value=1;
  return 0;
}


void Item_func_concat_ws::fix_length_and_dec()
{
  max_length=0;
  for (uint i=0 ; i < arg_count ; i++)
    max_length+=args[i]->max_length;
  if (max_length > MAX_BLOB_WIDTH)
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
  used_tables_cache|=separator->used_tables();
  const_item_cache&=separator->const_item();
}

void Item_func_concat_ws::update_used_tables()
{
  Item_func::update_used_tables();
  separator->update_used_tables();
  used_tables_cache|=separator->used_tables();
  const_item_cache&=separator->const_item();
}


String *Item_func_reverse::val_str(String *str)
{
  String *res = args[0]->val_str(str);
  char *ptr,*end;

  if ((null_value=args[0]->null_value))
    return 0;
  /* An empty string is a special case as the string pointer may be null */
  if (!res->length())
    return &empty_string;
  res=copy_if_not_alloced(str,res,res->length());
  ptr = (char *) res->ptr();
  end=ptr+res->length();
#ifdef USE_MB
  if (use_mb(default_charset_info) && !binary)
  {
    String tmpstr;
    tmpstr.copy(*res);
    char *tmp = (char *) tmpstr.ptr() + tmpstr.length();
    register uint32 l;
    while (ptr < end)
    {
      if ((l=my_ismbchar(default_charset_info, ptr,end)))
        tmp-=l, memcpy(tmp,ptr,l), ptr+=l;
      else
        *--tmp=*ptr++;
    }
    memcpy((char *) res->ptr(),(char *) tmpstr.ptr(), res->length());
  }
  else
#endif /* USE_MB */
  {
    char tmp;
    while (ptr < end)
    {
      tmp=*ptr;
      *ptr++=*--end;
      *end=tmp;
    }
  }
  return res;
}


void Item_func_reverse::fix_length_and_dec()
{
  max_length = args[0]->max_length;
}

/*
** Replace all occurences of string2 in string1 with string3.
** Don't reallocate val_str() if not needed
*/

/* TODO: Fix that this works with binary strings when using USE_MB */

String *Item_func_replace::val_str(String *str)
{
  String *res,*res2,*res3;
  int offset;
  uint from_length,to_length;
  bool alloced=0;
#ifdef USE_MB
  const char *ptr,*end,*strend,*search,*search_end;
  register uint32 l;
  bool binary_str = (args[0]->binary || args[1]->binary ||
		     !use_mb(default_charset_info));
#endif

  null_value=0;
  res=args[0]->val_str(str);
  if (args[0]->null_value)
    goto null;
  res2=args[1]->val_str(&tmp_value);
  if (args[1]->null_value)
    goto null;

  if (res2->length() == 0)
    return res;
#ifndef USE_MB
  if ((offset=res->strstr(*res2)) < 0)
    return res;
#else
  offset=0;
  if (binary_str && (offset=res->strstr(*res2)) < 0)
    return res;
#endif
  if (!(res3=args[2]->val_str(&tmp_value2)))
    goto null;
  from_length= res2->length();
  to_length=   res3->length();

#ifdef USE_MB
  if (!binary_str)
  {
    search=res2->ptr();
    search_end=search+from_length;
redo:
    ptr=res->ptr()+offset;
    strend=res->ptr()+res->length();
    end=strend-from_length+1;
    while (ptr < end)
    {
        if (*ptr == *search)
        {
          register char *i,*j;
          i=(char*) ptr+1; j=(char*) search+1;
          while (j != search_end)
            if (*i++ != *j++) goto skipp;
          offset= (int) (ptr-res->ptr());
          if (res->length()-from_length + to_length > max_allowed_packet)
            goto null;
          if (!alloced)
          {
            alloced=1;
            res=copy_if_not_alloced(str,res,res->length()+to_length);
          }
          res->replace((uint) offset,from_length,*res3);
	  offset+=(int) to_length;
          goto redo;
        }
skipp:
        if ((l=my_ismbchar(default_charset_info, ptr,strend))) ptr+=l;
        else ++ptr;
    }
  }
  else
#endif /* USE_MB */
    do
    {
      if (res->length()-from_length + to_length > max_allowed_packet)
        goto null;
      if (!alloced)
      {
        alloced=1;
        res=copy_if_not_alloced(str,res,res->length()+to_length);
      }
      res->replace((uint) offset,from_length,*res3);
      offset+=(int) to_length;
    }
    while ((offset=res->strstr(*res2,(uint) offset)) >= 0);
  return res;

null:
  null_value=1;
  return 0;
}


void Item_func_replace::fix_length_and_dec()
{
  max_length=args[0]->max_length;
  int diff=(int) (args[2]->max_length - args[1]->max_length);
  if (diff > 0 && args[1]->max_length)
  {						// Calculate of maxreplaces
    max_length= max_length/args[1]->max_length;
    max_length= (max_length+1)*(uint) diff;
  }
  if (max_length > MAX_BLOB_WIDTH)
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
}


String *Item_func_insert::val_str(String *str)
{
  String *res,*res2;
  uint start,length;

  null_value=0;
  res=args[0]->val_str(str);
  res2=args[3]->val_str(&tmp_value);
  start=(uint) args[1]->val_int()-1;
  length=(uint) args[2]->val_int();
  if (args[0]->null_value || args[1]->null_value || args[2]->null_value ||
      args[3]->null_value)
    goto null; /* purecov: inspected */
#ifdef USE_MB
  if (use_mb(default_charset_info) && !args[0]->binary)
  {
    start=res->charpos(start);
    length=res->charpos(length,start);
  }
#endif
  if (start > res->length()+1)
    return res;					// Wrong param; skip insert
  if (length > res->length()-start)
    length=res->length()-start;
  if (res->length() - length + res2->length() > max_allowed_packet)
    goto null;					// OOM check
  res=copy_if_not_alloced(str,res,res->length());
  res->replace(start,length,*res2);
  return res;
null:
  null_value=1;
  return 0;
}


void Item_func_insert::fix_length_and_dec()
{
  max_length=args[0]->max_length+args[3]->max_length;
  if (max_length > MAX_BLOB_WIDTH)
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
}


String *Item_func_lcase::val_str(String *str)
{
  String *res;
  if (!(res=args[0]->val_str(str)))
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  null_value=0;
  res=copy_if_not_alloced(str,res,res->length());
  res->casedn();
  return res;
}


String *Item_func_ucase::val_str(String *str)
{
  String *res;
  if (!(res=args[0]->val_str(str)))
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  null_value=0;
  res=copy_if_not_alloced(str,res,res->length());
  res->caseup();
  return res;
}


String *Item_func_left::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  long length  =(long) args[1]->val_int();

  if ((null_value=args[0]->null_value))
    return 0;
  if (length <= 0)
    return &empty_string;
#ifdef USE_MB
  if (use_mb(default_charset_info) && !binary)
    length = res->charpos(length);
#endif
  if (res->length() > (ulong) length)
  {						// Safe even if const arg
    if (!res->alloced_length())
    {						// Don't change const str
      str_value= *res;				// Not malloced string
      res= &str_value;
    }
    res->length((uint) length);
  }
  return res;
}


void Item_str_func::left_right_max_length()
{
  max_length=args[0]->max_length;
  if (args[1]->const_item())
  {
    int length=(int) args[1]->val_int();
    if (length <= 0)
      max_length=0;
    else
      set_if_smaller(max_length,(uint) length);
  }
}


void Item_func_left::fix_length_and_dec()
{
  left_right_max_length();
}


String *Item_func_right::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  long length  =(long) args[1]->val_int();

  if ((null_value=args[0]->null_value))
    return 0; /* purecov: inspected */
  if (length <= 0)
    return &empty_string; /* purecov: inspected */
  if (res->length() <= (uint) length)
    return res; /* purecov: inspected */
#ifdef USE_MB
  if (use_mb(default_charset_info) && !binary)
  {
    uint start=res->numchars()-(uint) length;
    if (start<=0) return res;
    start=res->charpos(start);
    tmp_value.set(*res,start,res->length()-start);
  }
  else
#endif
  {
    tmp_value.set(*res,(res->length()- (uint) length),(uint) length);
  }
  return &tmp_value;
}


void Item_func_right::fix_length_and_dec()
{
  left_right_max_length();
}


String *Item_func_substr::val_str(String *str)
{
  String *res  = args[0]->val_str(str);
  int32 start	= (int32) args[1]->val_int()-1;
  int32 length	= arg_count == 3 ? (int32) args[2]->val_int() : INT_MAX32;
  int32 tmp_length;

  if ((null_value=(args[0]->null_value || args[1]->null_value ||
		   (arg_count == 3 && args[2]->null_value))))
    return 0; /* purecov: inspected */
#ifdef USE_MB
  if (use_mb(default_charset_info) && !binary)
  {
    start=res->charpos(start);
    length=res->charpos(length,start);
  }
#endif
  if (start < 0 || (uint) start+1 > res->length() || length <= 0)
    return &empty_string;

  tmp_length=(int32) res->length()-start;
  length=min(length,tmp_length);

  if (!start && res->length() == (uint) length)
    return res;
  tmp_value.set(*res,(uint) start,(uint) length);
  return &tmp_value;
}


void Item_func_substr::fix_length_and_dec()
{
  max_length=args[0]->max_length;

  if (args[1]->const_item())
  {
    int32 start=(int32) args[1]->val_int()-1;
    if (start < 0 || start >= (int32) max_length)
      max_length=0; /* purecov: inspected */
    else
      max_length-= (uint) start;
  }
  if (arg_count == 3 && args[2]->const_item())
  {
    int32 length= (int32) args[2]->val_int();
    if (length <= 0)
      max_length=0; /* purecov: inspected */
    else
      set_if_smaller(max_length,(uint) length);
  }
}


String *Item_func_substr_index::val_str(String *str)
{
  String *res =args[0]->val_str(str);
  String *delimeter =args[1]->val_str(&tmp_value);
  int32 count = (int32) args[2]->val_int();
  uint offset;

  if (args[0]->null_value || args[1]->null_value || args[2]->null_value)
  {					// string and/or delim are null
    null_value=1;
    return 0;
  }
  null_value=0;
  uint delimeter_length=delimeter->length();
  if (!res->length() || !delimeter_length || !count)
    return &empty_string;		// Wrong parameters

#ifdef USE_MB
  if (use_mb(default_charset_info) && !binary)
  {
    const char *ptr=res->ptr();
    const char *strend = ptr+res->length();
    const char *end=strend-delimeter_length+1;
    const char *search=delimeter->ptr();
    const char *search_end=search+delimeter_length;
    int32 n=0,c=count,pass;
    register uint32 l;
    for (pass=(count>0);pass<2;++pass)
    {
      while (ptr < end)
      {
        if (*ptr == *search)
        {
	  register char *i,*j;
	  i=(char*) ptr+1; j=(char*) search+1;
	  while (j != search_end)
	    if (*i++ != *j++) goto skipp;
	  if (pass==0) ++n;
	  else if (!--c) break;
	  ptr+=delimeter_length;
	  continue;
	}
    skipp:
        if ((l=my_ismbchar(default_charset_info, ptr,strend))) ptr+=l;
        else ++ptr;
      } /* either not found or got total number when count<0 */
      if (pass == 0) /* count<0 */
      {
        c+=n+1;
        if (c<=0) return res; /* not found, return original string */
        ptr=res->ptr();
      }
      else
      {
        if (c) return res; /* Not found, return original string */
        if (count>0) /* return left part */
        {
	  tmp_value.set(*res,0,(ulong) (ptr-res->ptr()));
        }
        else /* return right part */
        {
	  ptr+=delimeter_length;
	  tmp_value.set(*res,(ulong) (ptr-res->ptr()), (ulong) (strend-ptr));
        }
      }
    }
  }
  else
#endif /* USE_MB */
  {
    if (count > 0)
    {					// start counting from the beginning
      for (offset=0 ;; offset+=delimeter_length)
      {
	if ((int) (offset=res->strstr(*delimeter,offset)) < 0)
	  return res;			// Didn't find, return org string
	if (!--count)
	{
	  tmp_value.set(*res,0,offset);
	  break;
	}
      }
    }
    else
    {					// Start counting at end
      for (offset=res->length() ; ; offset-=delimeter_length-1)
      {
	if ((int) (offset=res->strrstr(*delimeter,offset)) < 0)
	  return res;			// Didn't find, return org string
	if (!++count)
	{
	  offset+=delimeter_length;
	  tmp_value.set(*res,offset,res->length()- offset);
	  break;
	}
      }
    }
  }
  return (&tmp_value);
}

/*
** The trim functions are extension to ANSI SQL because they trim substrings
** They ltrim() and rtrim() functions are optimized for 1 byte strings
** They also return the original string if possible, else they return
** a substring that points at the original string.
*/


String *Item_func_ltrim::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  if ((null_value=args[0]->null_value))
    return 0;					/* purecov: inspected */
  char buff[MAX_FIELD_WIDTH];
  String tmp(buff,sizeof(buff));
  String *remove_str=args[1]->val_str(&tmp);
  uint remove_length;
  LINT_INIT(remove_length);

  if (!remove_str || (remove_length=remove_str->length()) == 0 ||
      remove_length > res->length())
    return res;

  char *ptr=(char*) res->ptr();
  char *end=ptr+res->length();
  if (remove_length == 1)
  {
    char chr=(*remove_str)[0];
    while (ptr != end && *ptr == chr)
      ptr++;
  }
  else
  {
    const char *r_ptr=remove_str->ptr();
    end-=remove_length;
    while (ptr < end && !memcmp(ptr,r_ptr,remove_length))
      ptr+=remove_length;
    end+=remove_length;
  }
  if (ptr == res->ptr())
    return res;
  tmp_value.set(*res,(uint) (ptr - res->ptr()),(uint) (end-ptr));
  return &tmp_value;
}


String *Item_func_rtrim::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  if ((null_value=args[0]->null_value))
    return 0; /* purecov: inspected */
  char buff[MAX_FIELD_WIDTH];
  String tmp(buff,sizeof(buff));
  String *remove_str=args[1]->val_str(&tmp);
  uint remove_length;
  LINT_INIT(remove_length);

  if (!remove_str || (remove_length=remove_str->length()) == 0 ||
      remove_length > res->length())
    return res;

  char *ptr=(char*) res->ptr();
  char *end=ptr+res->length();
#ifdef USE_MB
  char *p=ptr;
  register uint32 l;
#endif
  if (remove_length == 1)
  {
    char chr=(*remove_str)[0];
#ifdef USE_MB
    if (use_mb(default_charset_info) && !binary)
    {
      while (ptr < end)
      {
	if ((l=my_ismbchar(default_charset_info, ptr,end))) ptr+=l,p=ptr;
	else ++ptr;
      }
      ptr=p;
    }
#endif
    while (ptr != end  && end[-1] == chr)
      end--;
  }
  else
  {
    const char *r_ptr=remove_str->ptr();
#ifdef USE_MB
    if (use_mb(default_charset_info) && !binary)
    {
  loop:
      while (ptr + remove_length < end)
      {
	if ((l=my_ismbchar(default_charset_info, ptr,end))) ptr+=l;
	else ++ptr;
      }
      if (ptr + remove_length == end && !memcmp(ptr,r_ptr,remove_length))
      {
	end-=remove_length;
	ptr=p;
	goto loop;
      }
    }
    else
#endif /* USE_MB */
    {
      while (ptr + remove_length < end &&
	     !memcmp(end-remove_length,r_ptr,remove_length))
	end-=remove_length;
    }
  }
  if (end == res->ptr()+res->length())
    return res;
  tmp_value.set(*res,0,(uint) (end-res->ptr()));
  return &tmp_value;
}


String *Item_func_trim::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  if ((null_value=args[0]->null_value))
    return 0;					/* purecov: inspected */
  char buff[MAX_FIELD_WIDTH];
  String tmp(buff,sizeof(buff));
  String *remove_str=args[1]->val_str(&tmp);
  uint remove_length;
  LINT_INIT(remove_length);

  if (!remove_str || (remove_length=remove_str->length()) == 0 ||
      remove_length > res->length())
    return res;

  char *ptr=(char*) res->ptr();
  char *end=ptr+res->length();
  const char *r_ptr=remove_str->ptr();
  while (ptr+remove_length <= end && !memcmp(ptr,r_ptr,remove_length))
    ptr+=remove_length;
#ifdef USE_MB
  if (use_mb(default_charset_info) && !binary)
  {
    char *p=ptr;
    register uint32 l;
 loop:
    while (ptr + remove_length < end)
    {
      if ((l=my_ismbchar(default_charset_info, ptr,end))) ptr+=l;
      else ++ptr;
    }
    if (ptr + remove_length == end && !memcmp(ptr,r_ptr,remove_length))
    {
      end-=remove_length;
      ptr=p;
      goto loop;
    }
    ptr=p;
  }
  else
#endif /* USE_MB */
  {
    while (ptr + remove_length <= end &&
	   !memcmp(end-remove_length,r_ptr,remove_length))
      end-=remove_length;
  }
  if (ptr == res->ptr() && end == ptr+res->length())
    return res;
  tmp_value.set(*res,(uint) (ptr - res->ptr()),(uint) (end-ptr));
  return &tmp_value;
}


String *Item_func_password::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  if ((null_value=args[0]->null_value))
    return 0;
  if (res->length() == 0)
    return &empty_string;
  make_scrambled_password(tmp_value,res->c_ptr());
  str->set(tmp_value,16);
  return str;
}


String *Item_func_encrypt::val_str(String *str)
{
  String *res  =args[0]->val_str(str);

#ifdef HAVE_CRYPT
  char salt[3],*salt_ptr;
  if ((null_value=args[0]->null_value))
    return 0;
  if (res->length() == 0)
    return &empty_string;

  if (arg_count == 1)
  {					// generate random salt
    time_t timestamp=current_thd->query_start();
    salt[0] = bin_to_ascii( (ulong) timestamp & 0x3f);
    salt[1] = bin_to_ascii(( (ulong) timestamp >> 5) & 0x3f);
    salt[2] = 0;
    salt_ptr=salt;
  }
  else
  {					// obtain salt from the first two bytes
    String *salt_str=args[1]->val_str(&tmp_value);
    if ((null_value= (args[1]->null_value || salt_str->length() < 2)))
      return 0;
    salt_ptr= salt_str->c_ptr();
  }
  pthread_mutex_lock(&LOCK_crypt);
  char *tmp=crypt(res->c_ptr(),salt_ptr);
  str->set(tmp,(uint) strlen(tmp));
  str->copy();
  pthread_mutex_unlock(&LOCK_crypt);
  return str;
#else
  null_value=1;
  return 0;
#endif	/* HAVE_CRYPT */
}

void Item_func_encode::fix_length_and_dec()
{
  max_length=args[0]->max_length;
  maybe_null=args[0]->maybe_null;
}

String *Item_func_encode::val_str(String *str)
{
  String *res;
  if (!(res=args[0]->val_str(str)))
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  null_value=0;
  res=copy_if_not_alloced(str,res,res->length());
  sql_crypt.init();
  sql_crypt.encode((char*) res->ptr(),res->length());
  return res;
}

String *Item_func_decode::val_str(String *str)
{
  String *res;
  if (!(res=args[0]->val_str(str)))
  {
    null_value=1; /* purecov: inspected */
    return 0; /* purecov: inspected */
  }
  null_value=0;
  res=copy_if_not_alloced(str,res,res->length());
  sql_crypt.init();
  sql_crypt.decode((char*) res->ptr(),res->length());
  return res;
}


String *Item_func_database::val_str(String *str)
{
  if (!current_thd->db)
    str->length(0);
  else
    str->set((const char*) current_thd->db,(uint) strlen(current_thd->db));
  return str;
}

String *Item_func_user::val_str(String *str)
{
  THD *thd=current_thd;
  if (str->copy((const char*) thd->user,(uint) strlen(thd->user)) ||
      str->append('@') ||
      str->append(thd->host ? thd->host : thd->ip ? thd->ip : ""))
    return &empty_string;
  return str;
}

void Item_func_soundex::fix_length_and_dec()
{
  max_length=args[0]->max_length;
  set_if_bigger(max_length,4);
}


  /*
    If alpha, map input letter to soundex code.
    If not alpha and remove_garbage is set then skip to next char
    else return 0
    */

extern "C" {
extern const char *soundex_map;		// In mysys/static.c
}

static char get_scode(char *ptr)
{
  uchar ch=toupper(*ptr);
  if (ch < 'A' || ch > 'Z')
  {
					// Thread extended alfa (country spec)
    return '0';				// as vokal
  }
  return(soundex_map[ch-'A']);
}


String *Item_func_soundex::val_str(String *str)
{
  String *res  =args[0]->val_str(str);
  char last_ch,ch;
  if ((null_value=args[0]->null_value))
    return 0; /* purecov: inspected */

  if (str_value.alloc(max(res->length(),4)))
    return str; /* purecov: inspected */
  char *to= (char *) str_value.ptr();
  char *from= (char *) res->ptr(), *end=from+res->length();

  while (from != end && isspace(*from)) // Skip pre-space
    from++; /* purecov: inspected */
  if (from == end)
    return &empty_string;		// No alpha characters.
  *to++ = toupper(*from);		// Copy first letter
  last_ch = get_scode(from);		// code of the first letter
					// for the first 'double-letter check.
					// Loop on input letters until
					// end of input (null) or output
					// letter code count = 3
  for (from++ ; from < end ; from++)
  {
    if (!isalpha(*from))
      continue;
    ch=get_scode(from);
    if ((ch != '0') && (ch != last_ch)) // if not skipped or double
    {
       *to++ = ch;			// letter, copy to output
       last_ch = ch;			// save code of last input letter
    }					// for next double-letter check
  }
  for (end=(char*) str_value.ptr()+4 ; to < end ; to++)
    *to = '0';
  *to=0;				// end string
  str_value.length((uint) (to-str_value.ptr()));
  return &str_value;
}


/*
** Change a number to format '3,333,333,333.000'
** This should be 'internationalized' sometimes.
*/

Item_func_format::Item_func_format(Item *org,int dec) :Item_str_func(org)
{
  decimals=(uint) set_zone(dec,0,30);
}


String *Item_func_format::val_str(String *str)
{
  double nr	=args[0]->val();
  uint32 diff,length,str_length;
  uint dec;
  if ((null_value=args[0]->null_value))
    return 0; /* purecov: inspected */
  dec= decimals ? decimals+1 : 0;
  str->set(nr,decimals);
  str_length=str->length();
  if (nr < 0)
    str_length--;				// Don't count sign
  length=str->length()+(diff=(str_length- dec-1)/3);
  if (diff)
  {
    char *tmp,*pos;
    str=copy_if_not_alloced(&tmp_str,str,length);
    str->length(length);
    tmp=(char*) str->ptr()+length - dec-1;
    for (pos=(char*) str->ptr()+length ; pos != tmp; pos--)
      pos[0]=pos[- (int) diff];
    while (diff)
    {
      pos[0]=pos[-(int) diff]; pos--;
      pos[0]=pos[-(int) diff]; pos--;
      pos[0]=pos[-(int) diff]; pos--;
      pos[0]=',';
      pos--;
      diff--;
    }
  }
  return str;
}


void Item_func_elt::fix_length_and_dec()
{
  max_length=0;
  decimals=0;
  for (uint i=1 ; i < arg_count ; i++)
  {
    set_if_bigger(max_length,args[i]->max_length);
    set_if_bigger(decimals,args[i]->decimals);
  }
  maybe_null=1;					// NULL if wrong first arg
  with_sum_func= with_sum_func || item->with_sum_func;
  used_tables_cache|=item->used_tables();
  const_item_cache&=item->const_item();
}


void Item_func_elt::update_used_tables()
{
  Item_func::update_used_tables();
  item->update_used_tables();
  used_tables_cache|=item->used_tables();
  const_item_cache&=item->const_item();
}


double Item_func_elt::val()
{
  uint tmp;
  if ((tmp=(uint) item->val_int()) == 0 || tmp > arg_count)
  {
    null_value=1;
    return 0.0;
  }
  null_value=0;
  return args[tmp-1]->val();
}

longlong Item_func_elt::val_int()
{
  uint tmp;
  if ((tmp=(uint) item->val_int()) == 0 || tmp > arg_count)
  {
    null_value=1;
    return 0;
  }
  null_value=0;
  return args[tmp-1]->val_int();
}

String *Item_func_elt::val_str(String *str)
{
  uint tmp;
  if ((tmp=(uint) item->val_int()) == 0 || tmp > arg_count)
  {
    null_value=1;
    return NULL;
  }
  null_value=0;
  return args[tmp-1]->val_str(str);
}


void Item_func_make_set::fix_length_and_dec()
{
  max_length=arg_count-1;
  for (uint i=1 ; i < arg_count ; i++)
    max_length+=args[i]->max_length;
  used_tables_cache|=item->used_tables();
  const_item_cache&=item->const_item();
}


void Item_func_make_set::update_used_tables()
{
  Item_func::update_used_tables();
  item->update_used_tables();
  used_tables_cache|=item->used_tables();
  const_item_cache&=item->const_item();
}


String *Item_func_make_set::val_str(String *str)
{
  ulonglong bits;
  bool first_found=0;
  Item **ptr=args;
  String *result=&empty_string;

  bits=item->val_int();
  if ((null_value=item->null_value))
    return NULL;

  if (arg_count < 64)
    bits &= ((ulonglong) 1 << arg_count)-1;

  for (; bits; bits >>= 1, ptr++)
  {
    if (bits & 1)
    {
      String *res= (*ptr)->val_str(str);
      if (res)					// Skip nulls
      {
	if (!first_found)
	{					// First argument
	  first_found=1;
	  if (res != str)
	    result=res;				// Use original string
	  else
	  {
	    if (tmp_str.copy(*res))		// Don't use 'str'
	      return &empty_string;
	    result= &tmp_str;
	  }
	}
	else
	{
	  if (result != &tmp_str)
	  {					// Copy data to tmp_str
	    if (tmp_str.alloc(result->length()+res->length()+1) ||
		tmp_str.copy(*result))
	      return &empty_string;
	    result= &tmp_str;
	  }
	  if (tmp_str.append(',') || tmp_str.append(*res))
	    return &empty_string;
	}
      }
    }
  }
  return result;
}


String *Item_func_char::val_str(String *str)
{
  str->length(0);
  for (uint i=0 ; i < arg_count ; i++)
  {
    int32 num=(int32) args[i]->val_int();
    if (!args[i]->null_value)
#ifdef USE_MB
      if (use_mb(default_charset_info))
      {
        if (num&0xFF000000L) {
           str->append((char)(num>>24));
           goto b2;
        } else if (num&0xFF0000L) {
b2:        str->append((char)(num>>16));
           goto b1;
        } else if (num&0xFF00L) {   
b1:        str->append((char)(num>>8));
        }
      }
#endif
      str->append((char)num);
  }
  str->realloc(str->length());			// Add end 0 (for Purify)
  return str;
}


inline String* alloc_buffer(String *res,String *str,String *tmp_value,
			    ulong length)
{
  if (res->alloced_length() < length)
  {
    if (str->alloced_length() >= length)
    {
      (void) str->copy(*res);
      str->length(length);
      return str;
    }
    else
    {
      if (tmp_value->alloc(length))
	return 0;
      (void) tmp_value->copy(*res);
      tmp_value->length(length);
      return tmp_value;
    }
  }
  res->length(length);
  return res;
}


void Item_func_repeat::fix_length_and_dec()
{
  if (args[1]->const_item())
  {
    max_length=(long) (args[0]->max_length * args[1]->val_int());
    if (max_length >= MAX_BLOB_WIDTH)
    {
      max_length=MAX_BLOB_WIDTH;
      maybe_null=1;
    }
  }
  else
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
}

/*
** Item_func_repeat::str is carefully written to avoid reallocs
** as much as possible at the cost of a local buffer
*/

String *Item_func_repeat::val_str(String *str)
{
  uint length,tot_length;
  char *to;
  long count= (long) args[1]->val_int();
  String *res =args[0]->val_str(str);

  if (args[0]->null_value || args[1]->null_value)
    goto err;				// string and/or delim are null
  null_value=0;
  if (count <= 0)			// For nicer SQL code
    return &empty_string;
  if (count == 1)			// To avoid reallocs
    return res;
  length=res->length();
  if (length > max_allowed_packet/count)// Safe length check
    goto err;				// Probably an error
  tot_length= length*(uint) count;
  if (!(res= alloc_buffer(res,str,&tmp_value,tot_length)))
    goto err;

  to=(char*) res->ptr()+length;
  while (--count)
  {
    memcpy(to,res->ptr(),length);
    to+=length;
  }
  return (res);

err:
  null_value=1;
  return 0;
}


void Item_func_rpad::fix_length_and_dec()
{
  if (args[1]->const_item())
  {
    uint32 length= (uint32) args[1]->val_int();
    max_length=max(args[0]->max_length,length);
    if (max_length >= MAX_BLOB_WIDTH)
    {
      max_length=MAX_BLOB_WIDTH;
      maybe_null=1;
    }
  }
  else
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
}


String *Item_func_rpad::val_str(String *str)
{
  uint32 res_length,length_pad;
  char *to;
  const char *ptr_pad;
  int32 count= (int32) args[1]->val_int();
  String *res =args[0]->val_str(str);
  String *rpad = args[2]->val_str(str);

  if (!res || args[1]->null_value || !rpad)
    goto err;
  null_value=0;
  if (count <= (int32) (res_length=res->length()))
  {						// String to pad is big enough
    res->length(count);				// Shorten result if longer
    return (res);
  }
  length_pad= rpad->length();
  if ((ulong) count > max_allowed_packet || args[2]->null_value || !length_pad)
    goto err;
  if (!(res= alloc_buffer(res,str,&tmp_value,count)))
    goto err;

  to= (char*) res->ptr()+res_length;
  ptr_pad=rpad->ptr();
  for (count-= res_length; (uint32) count > length_pad; count-= length_pad)
  {
    memcpy(to,ptr_pad,length_pad);
    to+= length_pad;
  }
  memcpy(to,ptr_pad,(size_t) count);
  return (res);

 err:
  null_value=1;
  return 0;
}


void Item_func_lpad::fix_length_and_dec()
{
  if (args[1]->const_item())
  {
    uint32 length= (uint32) args[1]->val_int();
    max_length=max(args[0]->max_length,length);
    if (max_length >= MAX_BLOB_WIDTH)
    {
      max_length=MAX_BLOB_WIDTH;
      maybe_null=1;
    }
  }
  else
  {
    max_length=MAX_BLOB_WIDTH;
    maybe_null=1;
  }
}


String *Item_func_lpad::val_str(String *str)
{
  uint32 res_length,length_pad;
  char *to;
  const char *ptr_pad;
  ulong count= (long) args[1]->val_int();
  String *res= args[0]->val_str(str);
  String *lpad= args[2]->val_str(str);

  if (!res || args[1]->null_value || !lpad)
    goto err;
  null_value=0;
  if (count <= (res_length=res->length()))
  {						// String to pad is big enough
    res->length(count);				// Shorten result if longer
    return (res);
  }
  length_pad= lpad->length();
  if (count > max_allowed_packet || args[2]->null_value || !length_pad)
    goto err;

  if (res->alloced_length() < count)
  {
    if (str->alloced_length() >= count)
    {
      memcpy((char*) str->ptr()+(count-res_length),res->ptr(),res_length);
      res=str;
    }
    else
    {
      if (tmp_value.alloc(count))
	goto err;
      memcpy((char*) tmp_value.ptr()+(count-res_length),res->ptr(),res_length);
      res=&tmp_value;
    }
  }
  else
    bmove_upp((char*) res->ptr()+count,res->ptr()+res_length,res_length);
  res->length(count);

  to= (char*) res->ptr();
  ptr_pad= lpad->ptr();
  for (count-= res_length; count > length_pad; count-= length_pad)
  {
    memcpy(to,ptr_pad,length_pad);
    to+= length_pad;
  }
  memcpy(to,ptr_pad,(size_t) count);
  return (res);

 err:
  null_value=1;
  return 0;
}


String *Item_func_conv::val_str(String *str)
{
  String *res= args[0]->val_str(str);
  char *endptr,ans[65],*ptr;
  longlong dec;
  int from_base= (int) args[1]->val_int();
  int to_base= (int) args[2]->val_int();

  if (args[0]->null_value || args[1]->null_value || args[2]->null_value ||
      abs(to_base) > 36 || abs(to_base) < 2 ||
      abs(from_base) > 36 || abs(from_base) < 2 || !(res->length()))
  {
    null_value=1;
    return 0;
  }
  null_value=0;
  if (from_base < 0)
    dec= strtoll(res->c_ptr(),&endptr,-from_base);
  else
    dec= (longlong) strtoull(res->c_ptr(),&endptr,from_base);
  ptr= longlong2str(dec,ans,to_base);
  if (str->copy(ans,(uint32) (ptr-ans)))
    return &empty_string;
  return str;
}

#include <my_dir.h>				// For my_stat

String *Item_load_file::val_str(String *str)
{
  String *file_name;
  File file;
  MY_STAT stat_info;
  DBUG_ENTER("load_file");

  if (!(file_name= args[0]->val_str(str)) ||
      !(current_thd->master_access & FILE_ACL) ||
      !my_stat(file_name->c_ptr(), &stat_info, MYF(MY_WME)))
    goto err;
  if (!(stat_info.st_mode & S_IROTH))
  {
    /* my_error(ER_TEXTFILE_NOT_READABLE, MYF(0), file_name->c_ptr()); */
    goto err;
  }
  if (stat_info.st_size > (long) max_allowed_packet)
  {
    /* my_error(ER_TOO_LONG_STRING, MYF(0), file_name->c_ptr()); */
    goto err;
  }
  if (tmp_value.alloc(stat_info.st_size))
    goto err;
  if ((file = my_open(file_name->c_ptr(), O_RDONLY, MYF(0))) < 0)
    goto err;
  if (my_read(file, (byte*) tmp_value.ptr(), stat_info.st_size, MYF(MY_NABP)))
  {
    my_close(file, MYF(0));
    goto err;
  }
  tmp_value.length(stat_info.st_size);
  my_close(file, MYF(0));
  null_value = 0;
  return &tmp_value;

err:
  null_value = 1;
  DBUG_RETURN(0);
}


String* Item_func_export_set::val_str(String* str)
{
  ulonglong the_set = (ulonglong) args[0]->val_int();
  String yes_buf, *yes; 
  yes = args[1]->val_str(&yes_buf);
  String no_buf, *no; 
  no = args[2]->val_str(&no_buf);
  String *sep = NULL, sep_buf ; 

  uint num_set_values = 64;
  ulonglong mask = 0x1;
  str->length(0);

  /* Check if some argument is a NULL value */
  if (args[0]->null_value || args[1]->null_value || args[2]->null_value)
  {
    null_value=1;
    return 0;
  }
  switch(arg_count) {
  case 5:
    num_set_values = (uint) args[4]->val_int();
    if (num_set_values > 64)
      num_set_values=64;
    if (args[4]->null_value)
    {
      null_value=1;
      return 0;
    }
    /* Fall through */
  case 4:
    if (!(sep = args[3]->val_str(&sep_buf)))	// Only true if NULL
    {
      null_value=1;
      return 0;
    }
    break;
  case 3:
    sep_buf.set(",", 1);
    sep = &sep_buf;
  }
  null_value=0;

  for (uint i = 0; i < num_set_values; i++, mask = (mask << 1))
  {
    if (the_set & mask)
      str->append(*yes);
    else
      str->append(*no);
    if(i != num_set_values - 1)
      str->append(*sep);
  }
  return str;
}

void Item_func_export_set::fix_length_and_dec()
{
  uint length=max(args[1]->max_length,args[2]->max_length);
  uint sep_length=(arg_count > 3 ? args[3]->max_length : 1);
  max_length=length*64+sep_length*63;
}

String* Item_func_inet_ntoa::val_str(String* str)
{
  uchar buf[8], *p;
  ulonglong n = (ulonglong) args[0]->val_int();
  char num[4];
  // we do not know if args[0] is NULL until we have called
  // some val function on it if args[0] is not a constant!
  if ((null_value=args[0]->null_value))
    return 0;					// Null value
  str->length(0);
  int8store(buf,n);

  // now we can assume little endian
  // we handle the possibility of an 8-byte IP address
  // however, we do not want to confuse those who are just using
  // 4 byte ones
  
  for (p= buf + 8; p > buf+4 && p[-1] == 0 ; p-- ) ;
  num[3]='.';
  while (p-- > buf)
  {
    uint c = *p;
    uint n1,n2;					// Try to avoid divisions
    n1= c / 100;				// 100 digits
    c-= n1*100;
    n2= c / 10;					// 10 digits
    c-=n2*10;					// last digit
    num[0]=(char) n1+'0';
    num[1]=(char) n2+'0';
    num[2]=(char) c+'0';
    uint length=(n1 ? 4 : n2 ? 3 : 2);		// Remove pre-zero

    (void) str->append(num+4-length,length);
  }
  str->length(str->length()-1);			// Remove last '.';
  return str;
}