Re: [Bug #14015] pty regressed again, breaking expect and gcc's testsuite

Alan Cox
2009-09-04T15:28:07Z

> And if it _doesn't_ fix it, then I think we'll just have to revert the
> commits in question. We won't have time to root-cause it if the above
> isn't it.

In which case ppp will no longer work properly in some cases (ditto
other protocols) and things like the pppoe gateway wont work as they
don't in 2.6.30 - you need to go back to somewhere between 2.6.28/29 to
undo this, then apply the alternative locking patches to the
ppp/slip/ax25/etc ldiscs

Is the missing byte always part of the \r\n - that is handled slightly
specially by the n_tty ldisc code and has always been buggy if there is
flow control buffering - back to 1.3 and probably earlier. It happens on
real ttys too given sufficient flow control blockage because the char by
char opost stuff never did space/buffering checks. At least I don't think
the n_tty rework fixed it.