UNIBYTE_STR_AS_MULTIBYTE_P and UTF-8

[Chip Coldwell]

I'm looking at the C macro UNIBYTE_STR_AS_MULTIBYTE_P defined in
src/charset.h, which starts out with this

#define UNIBYTE_STR_AS_MULTIBYTE_P(str, length, bytes)          \
  (((str)[0] < 0x80 || (str)[0] >= 0xA0)                        \
   ? ((bytes) = 1)                                              \
   : /* lots, lots more */

So, if the value at str[0] is less than 0x80 or greater than 0xA0,
this macro returns the value one, and sets "bytes" to one.

That's fine for ASCII (always one byte wide) and ISO-8859-1 (with
special characters between 0xA0 and 0xFF), but what about UTF-8?
There are multibyte characters in UTF-8 with the first byte > 0xA0; it
doesn't seem to me that this macro will work for general UTF-8
strings.

Chip

--
Charles M. "Chip" Coldwell
Senior Software Engineer
Red Hat, Inc
978-392-2426