Date: Fri, 23 Oct 2009 18:32:38 +0200 (CEST) From: Alexander Best <alexbestms@math.uni-muenster.de> To: <rea-fbsd@codelabs.ru>, Dag-Erling Sm??rgrav <des@des.no> Cc: Antony Mawer <lists@mawer.org>, freebsd-hackers@freebsd.org, pluknet <pluknet@gmail.com>, ed@freebsd.org, rafan@freebsd.org Subject: Re: help needed to fix contrib/ee crash/exit when receiving SIGWINCH Message-ID: <permail-200910231632381e86ffa8000060e1-a_best01@message-id.uni-muenster.de> In-Reply-To: <8gJJDa6kRsCUwxK/zidtHIOFMRw@LbQSLh99U4wa807TkC1GazBU7WI>
next in thread | previous in thread | raw e-mail | index | archive | help
Eygene Ryabinkin schrieb am 2009-10-23:
> Gentlemen, good day.
> Fri, Oct 23, 2009 at 02:02:38PM +0200, Dag-Erling Sm??rgrav wrote:
> > src/contrib/ee/ee.c in 8:
> > in = wgetch(text_win);
> > if (in == -1)
> > exit(0); /* without this exit ee will go
> > into an
> > infinite loop if the network
> > session detaches */
> > >From the wgetch() man page:
> > Programmers concerned about portability should be prepared
> > for
> > either of two cases: (a) signal receipt does not interrupt
> > getch; (b) signal receipt interrupts getch and causes it to
> > return ERR with errno set to EINTR. Under the ncurses
> > implementation, handled signals never inter??? rupt getch.
> Hmm, we can transform this code to the following one:
> -----
> errno = 0;
> do {
> in = wgetch(text_win);
> } while (errno == EINTR);
> if (in == -1)
> exit(0);
> -----
> This won't help with FreeBSD's ncurses, but may be other variants
> will feel much better with such a event loop variant.
> > The real issue, though, is that when a SIGWINCH is caught, wgetch()
> > correctly returns KEY_RESIZE, but the next call to wgetch() returns
> > -1.
> > The next call after that is fine. I suspect the error lies
> > somewhere
> > inside kgetch() in contrib/ncurses/ncurses/base/lib_getch.c.
> The problem should be healed with the attached patch. And you're
> partly right: this is kgetch() that is returning ERR for the second
> wgetch(), but kgetch() shouldn't be blamed for this -- _nc_wgetch()
> should. At least in my opinion ;)
> Any views on this?
thanks a million. for me the patch works great. :) the sooner it gets
committed the better. ;) since this problem is not limited to freebsd it would
be nice if somebody could send the patch to the ncurses maintainers so all
OSes using ncurses can profit from it.
cheers.
alex
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?permail-200910231632381e86ffa8000060e1-a_best01>