Hi Peff,
On Thu, 27 Apr 2017, Jeff King wrote:
> On Wed, Apr 26, 2017 at 10:20:16PM +0200, Johannes Schindelin wrote:
>
> > diff --git a/builtin/mailsplit.c b/builtin/mailsplit.c
> > index 30681681c13..c0d88f97512 100644
> > --- a/builtin/mailsplit.c
> > +++ b/builtin/mailsplit.c
> > @@ -232,7 +232,7 @@ static int split_mbox(const char *file, const char *dir, int allow_bare,
> >
> > do {
> > peek = fgetc(f);
> > - } while (isspace(peek));
> > + } while (peek >= 0 && isspace(peek));
> > ungetc(peek, f);
>
> Are we guaranteed that EOF is a negative number?
No, you're right.
> Also, what is the behavior of ungetc when we pass it EOF?
According to the documentation, it would cast EOF to an unsigned char and
push that back. Definitely incorrect.
> It looks like POSIX does what we want (pushing EOF is a noop, and the
> stream retains its feof() status), but I don't know if there are other
> implementations to worry about.
That's not what my man page here says:
ungetc() pushes c back to stream, cast to unsigned char, where
it is available for subsequent read operations. Pushed-back
characters will be returned in reverse order; only one pushback is
guaranteed.
> Perhaps:
>
> /* soak up whitespace */
> while ((peek = fgetc(f)) != EOF) {
> if (!isspace(peek)) {
> ungetc(peek, f);
> break;
> }
> }
>
> would be more portable.
True. I changed it slightly differently, please see my reply to Hannes.
Thanks,
Dscho