maria-developers team mailing list archive

[Igor Babaev <igor@xxxxxxxxxxxx>]

On 01/08/2012 02:46 AM, Sergei Petrunia wrote:
> Hello Igor, Timour
> 
> Could anybody of please review the below fix? 
> additional details about the problem were posted at
> https://mariadb.atlassian.net/browse/MDEV-67.

Sergey,

After the discussion with you on skype I reviewed Timour's code

   if (mixed_implicit_grouping)
      tbl->table->maybe_null= 1;

and realized that it concerned a very special case when aggregate
functions were used together with fields in the select list.

Timour's code is ok for this case. So is yours.
Ok to push.

Regards,
Igor.

> 
> ----- Forwarded message from Sergey Petrunya <psergey@xxxxxxxxxxxx> -----
> 
> From: Sergey Petrunya <psergey@xxxxxxxxxxxx>
> To: commits@xxxxxxxxxxx
> X-Mailer: mail (GNU Mailutils 1.2)
> Date: Sun,  8 Jan 2012 14:43:17 +0400 (GST)
> Subject: [Commits] Rev 3377: BUG#912510: Crash in do_copy_not_null with
> 	semijoin=ON, firstmatch=ON,
> 	aggregate ... in file:///home/psergey/dev2/5.3-look46/
> 
> At file:///home/psergey/dev2/5.3-look46/
> 
> ------------------------------------------------------------
> revno: 3377
> revision-id: psergey@xxxxxxxxxxxx-20120108104314-xa6cxdbfive3elwf
> parent: igor@xxxxxxxxxxxx-20120103040636-nc6o55vsxqadd1n0
> committer: Sergey Petrunya <psergey@xxxxxxxxxxxx>
> branch nick: 5.3-look46
> timestamp: Sun 2012-01-08 14:43:14 +0400
> message:
>   BUG#912510: Crash in do_copy_not_null with semijoin=ON, firstmatch=ON, aggregate ...
>   - Create/use do_copy_nullable_row_to_notnull() function for ref access, which is used 
>     when copying from not-NULL field in table that can be NULL-complemented to not-NULL field.
> === modified file 'mysql-test/r/subselect_sj.result'
> --- a/mysql-test/r/subselect_sj.result	2011-12-24 16:55:10 +0000
> +++ b/mysql-test/r/subselect_sj.result	2012-01-08 10:43:14 +0000
> @@ -2152,4 +2152,21 @@
>  set optimizer_prune_level= @opl_901399;
>  set optimizer_switch= @os_091399;
>  DROP TABLE t1,t2;
> +#
> +# BUG#912510: Crash in do_copy_not_null with semijoin=ON, firstmatch=ON, aggregate ...
> +#
> +CREATE TABLE t1 ( a VARCHAR(1) NOT NULL );
> +INSERT INTO t1 VALUES ('k'),('l');
> +CREATE TABLE t2 ( b VARCHAR(1) NOT NULL, KEY(b) );
> +INSERT INTO t2 VALUES ('k'),('l');
> +CREATE TABLE t3 ( c VARCHAR(1) NOT NULL, KEY(c) );
> +INSERT INTO t3 VALUES ('m'),('n');
> +SELECT a, COUNT(*) FROM t1
> +WHERE a IN (
> +SELECT b FROM t2 force index(b), t3 force index(c)
> +WHERE c = b AND b = a
> +);
> +a	COUNT(*)
> +NULL	0
> +DROP TABLE t1, t2, t3;
>  set optimizer_switch=@subselect_sj_tmp;
> 
> === modified file 'mysql-test/r/subselect_sj_jcl6.result'
> --- a/mysql-test/r/subselect_sj_jcl6.result	2011-12-24 16:55:10 +0000
> +++ b/mysql-test/r/subselect_sj_jcl6.result	2012-01-08 10:43:14 +0000
> @@ -2166,6 +2166,23 @@
>  set optimizer_prune_level= @opl_901399;
>  set optimizer_switch= @os_091399;
>  DROP TABLE t1,t2;
> +#
> +# BUG#912510: Crash in do_copy_not_null with semijoin=ON, firstmatch=ON, aggregate ...
> +#
> +CREATE TABLE t1 ( a VARCHAR(1) NOT NULL );
> +INSERT INTO t1 VALUES ('k'),('l');
> +CREATE TABLE t2 ( b VARCHAR(1) NOT NULL, KEY(b) );
> +INSERT INTO t2 VALUES ('k'),('l');
> +CREATE TABLE t3 ( c VARCHAR(1) NOT NULL, KEY(c) );
> +INSERT INTO t3 VALUES ('m'),('n');
> +SELECT a, COUNT(*) FROM t1
> +WHERE a IN (
> +SELECT b FROM t2 force index(b), t3 force index(c)
> +WHERE c = b AND b = a
> +);
> +a	COUNT(*)
> +NULL	0
> +DROP TABLE t1, t2, t3;
>  set optimizer_switch=@subselect_sj_tmp;
>  #
>  # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off
> 
> === modified file 'mysql-test/t/subselect_sj.test'
> --- a/mysql-test/t/subselect_sj.test	2011-12-24 16:55:10 +0000
> +++ b/mysql-test/t/subselect_sj.test	2012-01-08 10:43:14 +0000
> @@ -1997,6 +1997,25 @@
>  
>  DROP TABLE t1,t2;
>  
> +--echo #
> +--echo # BUG#912510: Crash in do_copy_not_null with semijoin=ON, firstmatch=ON, aggregate ...
> +--echo #
> +CREATE TABLE t1 ( a VARCHAR(1) NOT NULL );
> +INSERT INTO t1 VALUES ('k'),('l');
> +
> +CREATE TABLE t2 ( b VARCHAR(1) NOT NULL, KEY(b) );
> +INSERT INTO t2 VALUES ('k'),('l');
> +
> +CREATE TABLE t3 ( c VARCHAR(1) NOT NULL, KEY(c) );
> +INSERT INTO t3 VALUES ('m'),('n');
> +
> +SELECT a, COUNT(*) FROM t1
> +  WHERE a IN (
> +    SELECT b FROM t2 force index(b), t3 force index(c)
> +    WHERE c = b AND b = a
> +  );
> +
> +DROP TABLE t1, t2, t3;
>  
>  # The following command must be the last one the file 
>  set optimizer_switch=@subselect_sj_tmp;
> 
> === modified file 'sql/field_conv.cc'
> --- a/sql/field_conv.cc	2011-12-11 09:34:44 +0000
> +++ b/sql/field_conv.cc	2012-01-08 10:43:14 +0000
> @@ -248,6 +248,25 @@
>    }
>  }
>  
> +/*
> +  Copy: (not-NULL field in table that can be NULL-complemented) -> (not-NULL
> +  field)
> +*/
> +static void do_copy_nullable_row_to_notnull(Copy_field *copy)
> +{
> +  if (*copy->null_row ||
> +      (copy->from_null_ptr && (*copy->from_null_ptr & copy->from_bit)))
> +  {
> +    copy->to_field->set_warning(MYSQL_ERROR::WARN_LEVEL_WARN,
> +                                WARN_DATA_TRUNCATED, 1);
> +    copy->to_field->reset();
> +  }
> +  else
> +  {
> +    (copy->do_copy2)(copy);
> +  }
> +
> +}
>  
>  /* Copy: (NULL-able field) -> (not NULL-able field) */
>  static void do_copy_not_null(Copy_field *copy)
> @@ -638,7 +657,15 @@
>        else if (to_field == to_field->table->next_number_field)
>          do_copy= do_copy_next_number;
>        else
> -        do_copy= do_copy_not_null;
> +      {
> +        if (!from_null_ptr)
> +        {
> +          null_row= &from->table->null_row;
> +          do_copy= do_copy_nullable_row_to_notnull;
> +        }
> +        else
> +          do_copy= do_copy_not_null;
> +      }
>      }
>    }
>    else if (to_field->real_maybe_null())
> 
> === modified file 'sql/sql_select.cc'
> --- a/sql/sql_select.cc	2011-12-24 16:55:10 +0000
> +++ b/sql/sql_select.cc	2012-01-08 10:43:14 +0000
> @@ -646,6 +646,9 @@
>        aggregate functions and non-aggregate fields, any non-aggregated field
>        may produce a NULL value. Set all fields of each table as nullable before
>        semantic analysis to take into account this change of nullability.
> +
> +      Note: this loop doesn't touch tables inside merged semi-joins, because
> +      subquery-to-semijoin conversion has not been done yet. This is intended.
>      */
>      if (mixed_implicit_grouping)
>        tbl->table->maybe_null= 1;
> 
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