Commit 6d0d03da authored by unknown's avatar unknown
Browse files

Fix QUOTE() to not reuse the input field for output, which resulted in 

incorrect results when the input was a constant across a multi-row SELECT
statement. (Bug #8248)


sql/item_strfunc.h:
  Add tmp_value member
sql/item_strfunc.cc:
  Always allocate a new string for QUOTE(), in case the field is being reused
  for multiple rows.
mysql-test/t/func_str.test:
  Add regression test
mysql-test/r/func_str.result:
  Add test results
parent faca00b5

mysql-test/r/func_str.result

+7 −0
Original line number Diff line number Diff line
@@ -297,3 +297,10 @@ quote(ltrim(concat(' ', 'a'))) 
select quote(trim(concat('    ', 'a')));

quote(trim(concat('    ', 'a')))

'a'

CREATE TABLE t1 SELECT 1 UNION SELECT 2 UNION SELECT 3;

SELECT QUOTE('A') FROM t1;

QUOTE('A')

'A'

'A'

'A'

DROP TABLE t1;

mysql-test/t/func_str.test

+5 −0
Original line number Diff line number Diff line
@@ -193,3 +193,8 @@ select trim(leading 'foo' from 'foo'); 


select quote(ltrim(concat('    ', 'a')));

select quote(trim(concat('    ', 'a')));



# Bad results from QUOTE(). Bug #8248

CREATE TABLE t1 SELECT 1 UNION SELECT 2 UNION SELECT 3;

SELECT QUOTE('A') FROM t1;

DROP TABLE t1;

sql/item_strfunc.cc

+5 −10
Original line number Diff line number Diff line
@@ -2183,18 +2183,13 @@ String *Item_func_quote::val_str(String *str) 
  for (from= (char*) arg->ptr(), end= from + arg_length; from < end; from++)

    new_length+= get_esc_bit(escmask, (uchar) *from);



  /*

    We have to use realloc() instead of alloc() as we want to keep the

    old result in arg

  */

  if (arg->realloc(new_length))

  if (tmp_value.alloc(new_length))

    goto null;



  /*

    As 'arg' and 'str' may be the same string, we must replace characters

    from the end to the beginning

    We replace characters from the end to the beginning

  */

  to= (char*) arg->ptr() + new_length - 1;

  to= (char*) tmp_value.ptr() + new_length - 1;

  *to--= '\'';

  for (start= (char*) arg->ptr(),end= start + arg_length; end-- != start; to--)

  {
@@ -2222,9 +2217,9 @@ String *Item_func_quote::val_str(String *str) 
    }

  }

  *to= '\'';

  arg->length(new_length);

  tmp_value.length(new_length);

  null_value= 0;

  return arg;

  return &tmp_value;



null:

  null_value= 1;

sql/item_strfunc.h

+1 −0
Original line number Diff line number Diff line
@@ -535,6 +535,7 @@ class Item_func_export_set: public Item_str_func 


class Item_func_quote :public Item_str_func

{

  String tmp_value;

public:

  Item_func_quote(Item *a) :Item_str_func(a) {}

  const char *func_name() const { return "quote"; }