Some messages held on admindb cannot display correctly becase of partial Unicode conversion error or
incomplete multi-byte character on mm_cfg.ADMINDB_PAGE_TEXT_LIMIT boundary.
Message character corruption has been occured in conditions below.
(1) Message charset/encoding is charset/encoding of multi-byte charaters.
(2) Message charset/encoding differs from web display charset/encoding.
(3) Message contains character that cannot convert to Unicode by using Python codec.
or
(3') Message body size exceeds mm_cfg.ADMINDB_PAGE_TEXT_LIMIT in bytes after decoding mime
and cut down along multi-byte charater's byte sequence.
Under these conditions, Unicode error occur in converting message charset/encoding and message
has remained not to convert charset/encoding.
A patch attached below solves (3) by using decode/encode with 'replace' error handling scheme,
and (3') by rounding on character boundary not to exceeds the limit in bytes after
character/encoding converted.
Note: Even If Message charset/encoding is same as web display charset/encoding, condition (3')
may produce invalid html, but patch below don't fix it.
If possible, please provide messages that meet
a) (1), (2) and (3)
b) (1), (2) and (3')
and a message which results in invalid HTML.
I would like to use these for unit tests.