Victor Snezhko <snezhko(at)indorsoft(dot)ru> writes:
> correct utf-8 byte sequence is 0xd18231, so it looks like we call
> tolower() somewhere on parts of multibyte characters, and it does the
> same as isspace() - it interprets it's argument as wide character, and
> converts it.
Indeed, and I am certainly wondering why we should not just say that
you've got a broken locale definition there. There is absolutely no
doubt that the ctype.h functions are defined to work on char, not wchar.
They have no business mangling high-bit-set bytes in a multibyte
encoding.
regards, tom lane