Commit ec0daa74 authored by unknown's avatar unknown
Browse files

#7874: CONCAT() gives wrong results mixing latin1 field and utf8 string literals 

We should not overwrite res if it is returned from a const item.
parent 985805ce

mysql-test/r/ctype_utf8.result

+12 −0
Original line number Diff line number Diff line
@@ -849,3 +849,15 @@ utf8_bin 6109 
utf8_bin	61

utf8_bin	6120

drop table t1;

CREATE TABLE t1 (

user varchar(255) NOT NULL default ''

) ENGINE=MyISAM DEFAULT CHARSET=latin1;

INSERT INTO t1 VALUES ('one'),('two');

SELECT CHARSET('a');

CHARSET('a')

utf8

SELECT user, CONCAT('<', user, '>') AS c FROM t1;

user	c

one	<one>

two	<two>

DROP TABLE t1;

mysql-test/t/ctype_utf8.test

+12 −0
Original line number Diff line number Diff line
@@ -681,3 +681,15 @@ SET collation_connection='utf8_general_ci'; 
-- source include/ctype_filesort.inc

SET collation_connection='utf8_bin';

-- source include/ctype_filesort.inc



#

# Bug #7874 CONCAT() gives wrong results mixing

# latin1 field and utf8 string literals

#

CREATE TABLE t1 (

	user varchar(255) NOT NULL default ''

) ENGINE=MyISAM DEFAULT CHARSET=latin1;

INSERT INTO t1 VALUES ('one'),('two');

SELECT CHARSET('a');

SELECT user, CONCAT('<', user, '>') AS c FROM t1;

DROP TABLE t1;

sql/item_strfunc.cc

+2 −1
Original line number Diff line number Diff line
@@ -275,7 +275,8 @@ String *Item_func_concat::val_str(String *str) 
			    current_thd->variables.max_allowed_packet);

	goto null;

      }

      if (res->alloced_length() >= res->length()+res2->length())

      if (!args[0]->const_item() && 

          res->alloced_length() >= res->length()+res2->length())

      {						// Use old buffer

	res->append(*res2);

      }