DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:to:from:subject:message-id:date:mime-version
	:content-type:content-transfer-encoding; q=dns; s=default; b=UeN
	LbKJHuwxRnRe6Bvh24SvMfRxtAcMKaqvKuEhjlzIhNZsLiwGShiMjVXSc1wlzCrJ
	YOzq55AfX0zyfraOrd1EFzh67IN2CHysZDnjDlTZzw5Ul5sgvZpkLJVpQDsFcwM4
	RU9Q/uf554pP/xfgXOIvUnI3O4KrJVFbe/NeMv1k=
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
To: cygwin@cygwin.com
From: =?UTF-8?Q?=c3=85ke_Rehnman?= <ake.rehnman@gmail.com>
Subject: Incorrect behavior in TIOCINQ ioctl
Message-ID: <d6a35f8b-3e4d-c8c6-4d3c-f15ccd72866d@gmail.com>
Date: Thu, 27 Feb 2020 22:38:48 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Note-from-DJ: This may be spam

Hi,

I recently ran in to some troubles with the TIOCINQ ioctl. I am 
wondering if the cygwin implementation is correct... It seems if there 
were any existing framing overrun errors etc etc  before calling the 
TIOCINQ ioctl it is returning an error (EINVAL). Reading through linux 
implmentation of TIOCINQ does simply return number of pending chars 
without any clearing or checking for errors.

I suggest the whole if (ev & CE_FRAME  ...... ) is removed.

Excerpt from fhandler_serial.cc:

/* ioctl: */
int
fhandler_serial::ioctl (unsigned int cmd, void *buf)
{
.
.
   if (!ClearCommError (get_handle (), &ev, &st))
     {
       __seterrno ();
       res = -1;
     }
.
.
.
      case TIOCINQ:
        if (ev & CE_FRAME || ev & CE_IOE || ev & CE_OVERRUN || ev & 
CE_RXOVER
        || ev & CE_RXPARITY)
      {
        set_errno (EINVAL);    /* FIXME: Use correct errno */
        res = -1;
      }
      else
         ipbuf = st.cbInQue;
      break;


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple