Re: [PATCH 10/26] Check for EOF while parsing mails

[Jeff King]

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?  Also, what is the
behavior of ungetc when we pass it EOF?

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.

Perhaps:

  /* soak up whitespace */
  while ((peek = fgetc(f)) != EOF) {
        if (!isspace(peek)) {
                ungetc(peek, f);
                break;
        }
  }

would be more portable.

-Peff