Item_in_subselect::val_int incorrectly called for a DELETE statement in prepared mode resulting in failed assert.

[Timour Katchaounov]

When run with --ps-protocol the test file subselect.test crashes with
a failed assert as follows:

DELETE FROM t1 WHERE topic IN (SELECT DISTINCT topic FROM t2 WHERE NOT
EXISTS(SELECT * FROM t3 WHERE numeropost=topic))

Results in Item_in_subselect::val_int() being called incorrectly,
resulting in a failed assert.

    function=0xd178a0 "virtual longlong Item_in_subselect::val_int()") at assert.c:81
#7 0x000000000064787b in Item_in_subselect::val_int (this=0x4eea150) at item_subselect.cc:1287
#8 0x000000000070ba76 in SQL_SELECT::skip_record (this=0x4e8efa0, thd=0x3d0d018) at opt_range.h:916
#9 0x000000000078d7cc in mysql_delete (thd=0x3d0d018, table_list=0x3df6140, conds=0x4eea150, order=0x3df56b0, limit=18446744073709551615, options=0,
    reset_auto_increment=false) at sql_delete.cc:321
#10 0x00000000006bcc39 in mysql_execute_command (thd=0x3d0d018) at sql_parse.cc:3313
#11 0x0000000000781c37 in Prepared_statement::execute (this=0x4ec8a58, expanded_query=0x7f6b31f7a950, open_cursor=false) at sql_prepare.cc:3631
#12 0x0000000000780de3 in Prepared_statement::execute_loop (this=0x4ec8a58, expanded_query=0x7f6b31f7a950, open_cursor=false, packet=0x3c951f2 "",
    packet_end=0x3c951f2 "") at sql_prepare.cc:3306
#13 0x000000000077ebb9 in mysqld_stmt_execute (thd=0x3d0d018, packet_arg=0x3c951e9 "T\001", packet_length=9) at sql_prepare.cc:2516
#14 0x00000000006b6ffe in dispatch_command (command=COM_STMT_EXECUTE, thd=0x3d0d018, packet=0x3c951e9 "T\001", packet_length=9) at sql_parse.cc:1164
#15 0x00000000006b653e in do_command (thd=0x3d0d018) at sql_parse.cc:903

[Timour Katchaounov (timour)]

Test case extracted from subselect.test:

CREATE TABLE t1 (
  mot varchar(30) character set latin1 NOT NULL default '',
  topic mediumint(8) unsigned NOT NULL default '0',
  date date NOT NULL default '0000-00-00',
  pseudo varchar(35) character set latin1 NOT NULL default '',
  PRIMARY KEY (mot,pseudo,date,topic),
  KEY pseudo (pseudo,date,topic),
  KEY topic (topic)
) ENGINE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC;

CREATE TABLE t2 (
  mot varchar(30) character set latin1 NOT NULL default '',
  topic mediumint(8) unsigned NOT NULL default '0',
  date date NOT NULL default '0000-00-00',
  pseudo varchar(35) character set latin1 NOT NULL default '',
  PRIMARY KEY (mot,pseudo,date,topic),
  KEY pseudo (pseudo,date,topic),
  KEY topic (topic)
) ENGINE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC;

CREATE TABLE t3 (
  numeropost mediumint(8) unsigned NOT NULL auto_increment,
  maxnumrep int(10) unsigned NOT NULL default '0',
  PRIMARY KEY (numeropost),
  UNIQUE KEY maxnumrep (maxnumrep)
) ENGINE=MyISAM CHARSET=latin1;

INSERT INTO t1 VALUES ('joce','1','','joce'),('test','2','','test');

INSERT INTO t2 VALUES ('joce','1','','joce'),('test','2','','test');

INSERT INTO t3 VALUES (1,1);

-- this statement works fine
DELETE FROM t1
WHERE topic IN (SELECT DISTINCT topic FROM t2
                WHERE NOT EXISTS(SELECT * FROM t3 WHERE numeropost=topic));

prepare st1 from "
DELETE FROM t1
WHERE topic IN (SELECT DISTINCT topic FROM t2
                WHERE NOT EXISTS(SELECT * FROM t3 WHERE numeropost=topic));
";

-- this statement results in a failed assert
execute st1;

[Timour Katchaounov (timour)]

Much simpler test case:

create table t1 (c1 int);
create table t2 (c2 int);
insert into t1 values (1),(2);
insert into t2 values (2),(3);

prepare st1 from "DELETE FROM t1 WHERE c1 IN (SELECT c2 FROM t2)";
execute st1;