Commit 8487aa5a authored by unknown's avatar unknown
Browse files

Fix for BUG#7455. 

The fix checks if the trim string argument is NULL. If so, the standard
mandates that the function result must be also NULL.


mysql-test/r/func_str.result:
  added test result
mysql-test/t/func_str.test:
  Added test for NULL arguments.
sql/item_strfunc.cc:
  Test if the trim argument is NULL.
parent 47efc5f3

mysql-test/r/func_str.result

+6 −0
Original line number Diff line number Diff line
@@ -697,3 +697,9 @@ quote(ltrim(concat(' ', 'a'))) 
select quote(trim(concat('    ', 'a')));

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

'a'

select trim(null from 'kate') as "must_be_null";

must_be_null

NULL

select trim('xyz' from null) as "must_be_null";

must_be_null

NULL

mysql-test/t/func_str.test

+8 −0
Original line number Diff line number Diff line
@@ -435,3 +435,11 @@ drop table t1; 


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

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



#

# Bug#7455 unexpected result: TRIM(<NULL> FROM <whatever>) gives NOT NULL

# According to ANSI if one of the TRIM arguments is NULL, then the result

# must be NULL too.

#

select trim(null from 'kate') as "must_be_null";

select trim('xyz' from null) as "must_be_null";

sql/item_strfunc.cc

+10 −1
Original line number Diff line number Diff line
@@ -1302,9 +1302,18 @@ String *Item_func_trim::val_str(String *str) 
    return 0;					/* purecov: inspected */

  char buff[MAX_FIELD_WIDTH];

  String tmp(buff,sizeof(buff),res->charset());

  String *remove_str= (arg_count==2) ? args[1]->val_str(&tmp) : &remove;

  uint remove_length;

  LINT_INIT(remove_length);

  String *remove_str; /* The string to remove from res. */



  if (arg_count == 2)

  {

    remove_str= args[1]->val_str(&tmp);

    if ((null_value= args[1]->null_value))

      return 0;

  }

  else

    remove_str= &remove; /* Default value. */



  if (!remove_str || (remove_length=remove_str->length()) == 0 ||

      remove_length > res->length())