[Toybox] [PATCH] telnetd: don't exit if waitpid() returns 0.

[Rob Landley]

On 3/17/21 11:56 PM, enh via Toybox wrote:
> Noticed while using telnetd to manually test some telnet fixes: telnetd
> would sometimes exit when I'd disconnect because it couldn't find pid 0
> on its list of sessions.
> 
> I've not seen obscure exits because select() times out, but I've also
> changed that `return` to an error_exit() so we'll at least know what's
> happened if that ever occurs.
> 
> Also use <arpa/telnet.h> rather than manually #define'ing its constants,
> use the FLAG() macro throughout, and xsetsockopt(). Don't pointlessly
> set errno to 0 at the start of main and then never look at it again.

You've been poking at unexpected bits of pending recently. My post-sh todo has
the "pending" files from Android.bp as prioritized for cleanup, ala:

    "toys/pending/dd.c",
    "toys/pending/diff.c",
    "toys/pending/expr.c",
    "toys/pending/getfattr.c",
    "toys/pending/getopt.c",
    "toys/pending/lsof.c",
    "toys/pending/modprobe.c",
    "toys/pending/more.c",
    "toys/pending/readelf.c",
    "toys/pending/stty.c",
    "toys/pending/traceroute.c",
    "toys/pending/tr.c",
    "toys/pending/vi.c",

Neither init nor telnet are on there. (Not complaining, happy for the help, but
is there something I should know about?)

Rob