Commit f22fde21 authored by monty@mashka.mysql.fi's avatar monty@mashka.mysql.fi
Browse files

Fixed max_key_length when using UNIQUE keys. 

This fixed a bug in GROUP BY on a BLOB column with NULL values.
parent fc8a7895

myisam/mi_create.c

+1 −1
Original line number Diff line number Diff line
@@ -224,7 +224,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs, 
  if (uniques)

  {

    max_key_block_length= MI_KEY_BLOCK_LENGTH;

    max_key_length= MI_UNIQUE_HASH_LENGTH;

    max_key_length= MI_UNIQUE_HASH_LENGTH + pointer;

  }



  for (i=0, keydef=keydefs ; i < keys ; i++ , keydef++)

myisam/mi_unique.c

+10 −1
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ my_bool mi_check_unique(MI_INFO *info, MI_UNIQUEDEF *def, byte *record, 
{

  my_off_t lastpos=info->lastpos;

  MI_KEYDEF *key= &info->s->keyinfo[def->key];

  uchar *key_buff=info->lastkey+info->s->base.max_key_length;

  uchar *key_buff=info->lastkey2;

  DBUG_ENTER("mi_check_unique");



  mi_unique_store(record+key->seg->start, unique_hash);
@@ -80,8 +80,17 @@ ha_checksum mi_unique_hash(MI_UNIQUEDEF *def, const byte *record) 
    if (keyseg->null_bit)

    {

      if (record[keyseg->null_pos] & keyseg->null_bit)

      {

	/*

	  Change crc in a way different from an empty string or 0.

	  (This is an optimisation;  The code will work even if this isn't

	  done)

	*/

	crc=((crc << 8) + 511+

	     (crc >> (8*sizeof(ha_checksum)-8)));

	continue;

      }

    }

    pos= record+keyseg->start;

    if (keyseg->flag & HA_VAR_LENGTH)

    {

mysql-test/r/group_by.result

+8 −0
Original line number Diff line number Diff line
@@ -102,3 +102,11 @@ pid c1id c2id value id active id active 
1	4	NULL	4	4	Yes	NULL	NULL

max(value)

4

a	count(*)

NULL	9

	3

b	1

a	count(*)

NULL	9

	3

b	1

mysql-test/t/group_by.test

+11 −0
Original line number Diff line number Diff line
@@ -312,3 +312,14 @@ m.c1id = c1.id AND c1.active = 'Yes' LEFT JOIN t3 AS c2 ON m.c2id = 
c2.id AND c2.active = 'Yes' WHERE m.pid=1  AND (c1.id IS NOT NULL OR c2.id IS 

NOT NULL);

drop table t1,t2,t3;



#

# Test bug in GROUP BY on BLOB that is NULL or empty

#



create table t1 (a blob null);

insert into t1 values (NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(""),(""),(""),("b");

select a,count(*) from t1 group by a;

set option sql_big_tables=1;

select a,count(*) from t1 group by a;

drop table t1;