trim() spec

Hi,

Can you tell me trim() spec, please ? (This problem has been
discussed in pgsql-jp ML. )

In trim(trailing 'abc' from '123cbabc') function, 'abc' means
~'[abc]'.

pgbash> select trim(trailing 'abc' from '123cbabc');
rtrim
-----
123 <==== it is not "123cb"!!
(1 row)

In current trim() function, MULTIBYTE string is broken.

pgbash> select trim(trailing '0x8842' from '0xB1428842');
--~~ ~~--~~
rtrim
-----
0xB1 <==== MULTIBYTE string broken (This is a bug.)
(1 row)

If trim(trailing 'abc' from '123cbabc') returns "123cb", current
trim() spec is broken. However, the spec that 'abc' means ~'[abc]'
is ugly. It seems that this ugly spec isn't used for any kind of
functions argument and SQL expression except for trim().

How do you think about the trim() spec ?

--
Regards,
SAKAIDA Masaaki -- Osaka, Japan