Pádraig Brady wrote:
To me, mbrtowc returning 0 for empty input is not surprising.
Also POSIX says for mbr{len,towc} that they shall return 0
"If the next n or fewer bytes complete the character that corresponds to the
null wide character
At least 1 byte is needed to represent a null wide character.
Therefore, zero bytes cannot possibly complete a null wide character,
which means mbrtowc on empty input cannot return 0 if it wants to
conform to POSIX and/or C11.
A similar argument shows why mbrtowc can't return (size_t) -1 on empty
input: it's because you need at least 1 byte to represent an encoding error.
Thanks for the typo fix, by the way.
