OpenSSH, Cygwin, eXceed, and SIGINT

Scott Crosby scrosby at
Thu Jun 28 23:31:10 EST 2001

	Both ISIG and ICANON are being cleared (both with and without x11
forwarding enabled,) vi enter_raw_mode() in sshtty.c.  The part that
perplexes me is that the bug only shows up when x11 forwarding is enabled.
Any ideas?

-----Original Message-----
From: Gert Doering [mailto:gert at]
Sent: Wednesday, June 27, 2001 5:36 PM
To: Scott Crosby; 'openssh-unix-dev at'
Subject: Re: OpenSSH, Cygwin, eXceed, and SIGINT


On Wed, Jun 27, 2001 at 01:48:43PM -0400, Scott Crosby wrote:
> 	When logging into an HP-UX 10.2 system from a Windows NT machine
> running Cygwin and openssh 2.9p2, control-c sends a sigint to the ssh
> on the NT system, thus killing the ssh process.  Interestingly enough,
> behavior is only observed when using X11 forwarding.  I can eliminate the
> behavior by changing clientloop.c to ignore SIGINT (signal(SIGINT,
> ) but then I'm bak to the old behavior of the remote shell ignoring

If the client were running on a unix machine, I'd say that the "ISIG" and/or
"ICANON" flags of the tty control structure are not cleared (thus making
the local terminal handler interpret ctrl-c and generate a SIGINT).

As this is Cygwin, I have no idea, never used this, and I have no idea
whether they have POSIX tty "things" (POSIX termios structure, and
underlying logic).

USENET is *not* the non-clickable part of WWW!
Gert Doering - Munich, Germany
gert at
fax: +49-89-35655025
gert.doering at

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