On 2023-07-24 15:58, Bruno Haible wrote:
Paul Eggert wrote:
in UTF-8 the byte sequence E0 80 is not an incomplete character
(in the sense that additional bytes may lead to a complete character),
because every byte you append to E0 80 causes glibc mbrtoc32 to return
(size_t) -1. Yet glibc mbrtoc32 returns (size_t) -2 for E0 80.
And gnulib/lib/unistr/u8-mbtouc-aux.c does it wrong as well!
The return value for E0 {80..9F} should be (size_t) -1, because
U+0800 is E0 A0 80.
I'll fix the gnulib part soon. Very good point. It looks like few people
understood the implications of
https://www.unicode.org/versions/Unicode15.0.0/ch03.pdf page 125, table 3-7.
I hope we don't need to replace mbrtoc32 merely because of this obscure
issue. Or at least if mbrtoc32 can be replaced, I hope an application
can disable replacement merely because of this issue, assuming the
application doesn't need to worry about the issue and there is a
performance benefit to not replacing.
