On Thu, Nov 16, 2017 at 09:57:06AM -0500, Ted Unangst wrote:
> Ingo Schwarze wrote:
> > [EILSEQ]
> > A wide-character code that does not correspond to a valid
> > character has been detected.
> >
> > That means that the functions are *required* to fail ("shall fail")
> > if encoding errors can be detected, that -1 must be returned, and
> > that errno must be set.
>
> I understand what you're saying, but I think strictly following the standard
> is a bit silly here. This is a very poor way for the fastidious programmer to
> check for valid byte sequences. Also, nobody is actually that careful. I'm
> actually kind of surprised that such a check is performed. Usually the rule is
> that the caller is responsible for checking. strdup doesn't return an error
> for a NULL pointer. I would expect if I printf "\xc0\x80" that I will get the
> two bytes c0 80 as output.
>
> There's some danger of slippery slope here, which parts of the standard are
> safe to ignore and which aren't. It's reasonable to argue it's best not to
> ignore anything, but I feel pretty good about ignoring this rule as an
> exception.
>
I agree with Ted.
I would expect EILSEQ during %lc and %ls conversions which explicitly
expect wide characters as arguments, but not for arbitrary data that
happens to be part of the format string.
