Commit 581d4d23 authored by unknown's avatar unknown
Browse files

Bug#19599 duplication of information_schema column value in a CONCAT expr with user var 

mark result string using String::mark_as_const()
which prevents CONCAT from reusing it as a buffer
for concatenation result.


mysql-test/r/information_schema.result:
  Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
  test case
mysql-test/t/information_schema.test:
  Bug#19599 duplication of information_schema column value in a CONCAT expr with user var
  test case
parent 6c431a5e

mysql-test/r/information_schema.result

+9 −0
Original line number Diff line number Diff line
@@ -1121,3 +1121,12 @@ NULL test v2 select 1 AS `1` NONE NO mysqltest_1@localhost DEFINER 
drop view v1, v2;

drop table t1;

drop user mysqltest_1@localhost;

set @a:= '.';

create table t1(f1 char(5));

create table t2(f1 char(5));

select concat(@a, table_name), @a, table_name

from information_schema.tables where table_schema = 'test';

concat(@a, table_name)	@a	table_name

.t1	.	t1

.t2	.	t2

drop table t1,t2;

mysql-test/t/information_schema.test

+10 −0
Original line number Diff line number Diff line
@@ -838,3 +838,13 @@ connection default; 
drop view v1, v2;

drop table t1;

drop user mysqltest_1@localhost;



#

# Bug#19599 duplication of information_schema column value in a CONCAT expr with user var

#

set @a:= '.';

create table t1(f1 char(5));

create table t2(f1 char(5));

select concat(@a, table_name), @a, table_name

from information_schema.tables where table_schema = 'test';

drop table t1,t2;

sql/item_strfunc.h

+1 −0
Original line number Diff line number Diff line
@@ -674,6 +674,7 @@ class Item_func_conv_charset :public Item_str_func 
                                 str->charset(), conv_charset, &errors))

        null_value= 1;

      use_cached_value= 1;

      str_value.mark_as_const();

      safe= (errors == 0);

    }

    else