Re: [Chicken-hackers] [PATCH] Handle EINTR properly in getc()

[John Cowan]

Peter Bex scripsit:

> It turns out that errno is *not* cleared in between calls, 

This is a general principle of Posix programming: you MUST NOT examine
errno unless you already know you have an error, whether by a -1 return,
or by a -1 return plus a call to ferror().

> +    return (errno == EINTR && !feof(fp)) ? C_fix(-1) : C_SCHEME_END_OF_FILE;

I recommend (ferror(fp) && errno == EINTR) instead.  It's clearer to use
ferror() rather than !feof(), and the opposite order is more natural:
make sure there is an error, then check what error it is.  This applies
to all uses of !feof() in this patch.

-- 
Not to perambulate                 John Cowan <address@hidden>
    the corridors                  http://www.ccil.org/~cowan
during the hours of repose
    in the boots of ascension.       --Sign in Austrian ski-resort hotel