Re: HEAD tty seems to drop characters

On Sun, 2009-08-02 at 14:31 +0200, Ed Schouten wrote:
> Hi Kostik,
> 
> * Kostik Belousov <kostikbel_at_gmail.com> wrote:
> > I run a screen(1), where I tried to copy large portion of output and
> > paste it into vi. This resulted in the loss of the characters at random
> > points inside the pasted text.
> 
> I already took some time to investigate the issue. I have attached a
> patch that should already improve the situation:
> 
> - write() on a pseudo-terminal master also accounted the data that was
>   read into the kernel, but couldn't be passed to the TTY (which is
>   likely to happen in non-blocking mode).
> 
> - There was also a small unrelated issue; input on a TTY which has been
>   configured in block (bypass) mode wouldn't set the input high water
>   mark.
> 
> For some reason, the data loss doesn't occur when SSHing to myself
> multiple times, but still causes screen(1) to drop some bytes later on.
> 
> Even though it's always very easy to blame other applications, I suspect
> this may be because I reduced the input buffer size from 8 KB to 2 KB
> per pseudo-terminal. Maybe screen(1) can't deal with this. To be
> investigated...

I'm pretty sure that I've seen this without screen involved.  Just
trying to cut / paste pkg-plist entries from an xterm or gnome-terminal
(IIRC, I tried both) into vi.  It worked as long as I took smaller
chunks, but corrupted things if I tried to copy the whole plist in one
shot.

robert.

-- 
Robert Noland <rnoland_at_FreeBSD.org>
FreeBSD