Bug #21531 EXPORT_SET() doesn't accept args with coercible character sets

Description:
A typo in Item_func_export_set::fix_length_and_dec() caused the function to require all arguments to have identical collations.

How to repeat:
select export_set(3, _latin1'foo', _utf8'bar', ',', 4);

Suggested fix:
Put MY_COLL_ALLOW_CONV inside the agg_arg_charsets() function, not outside it.

Remove the default value for the flags argument of agg_arg_charsets() while we're at it.

Note: this bug is only in 4.1; 5.0+ don't have it (or have already been fixed).

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/10190

ChangeSet@1.2541, 2006-08-09 02:48:34-06:00, tsmith@siva.hindu.god +2 -0
  Bug #21531: EXPORT_SET() doesn't accept args with coercible character sets
  
  - Remove default value for 'flags' argument of agg_arg_charsets()
  - Move MY_COLL_ALLOW_CONV inside the agg_arg_charsets() function, not outside it,
    in Item_func_export_set::fix_length_and_dec()

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/10802

ChangeSet@1.2537, 2006-08-23 18:02:31-06:00, tsmith@siva.hindu.god +4 -0
  Bug #21531: EXPORT_SET() doesn't accept args with coercible character sets
  
  - Fix typo in Item_func_export_set::fix_length_and_dec() which caused character set aggregation to fail
  - Remove default argument from last arg of agg_arg_charsets() function, to reduce potential errors

Pushed to 5.0.25

Noted in 4.1.22, 5.0.25 changelogs.