Re: possible bugfix for CHAR_LEADING_CODE() for multibyte raw bytes

[Eli Zaretskii]

> Date: Sun, 28 Apr 2024 10:14:53 +0000
> From: Danny McClanahan <dmcc2@hypnicjerk.ai>
> 
> While implementing the multibyte encoding scheme, I found what seemed to be 
> an error in `CHAR_LEADING_CODE()` for raw bytes (multibyte codepoints encoded 
> using two bytes which encode a single raw byte), where the multibyte code `c` 
> isn't shifted downward the way it is in `char_string()` (see diff for fix at 
> bottom).

Does the change you propose actually affect the result?  The
"((c >> 6) & 0x01)" part takes just the LSB of (c >> 6), and
that doesn't seem to be affected by running c through
CHAR_TO_BYTE8, does it?

The leading byte of a multibyte sequence for raw bytes is either 0xC0
or 0xC1.  That's what that part is trying to compute.  Am I missing
something?