Re: [PATCH] Cygwin: pty: Treat CR/NL in accept_input() the same as in transfer_input()

Thanks! Pushed.

On Wed, 24 Jun 2026 00:14:19 -0700
Mark Geisert wrote:
> Hi Takashi,
> 
> On 6/23/2026 6:04 AM, Takashi Yano wrote:
> > Hi Mark,
> > 
> > Thanks for reviewing!
> > 
> > On Tue, 23 Jun 2026 00:41:11 -0700
> > Mark Geisert wrote:
> >> Hi Takashi,
> >>
> >> On 6/12/2026 5:47 AM, Takashi Yano wrote:
> >>> In transfer_input(), CR and NL in the data transferred to nat-pipe
> >>> is treated as follows:
> >>>     1) If pseudo console is activated, convert NL to CR.
> >>>     2) If pseudo console is disabled, convert CR to NL.
> >>> This conversion is necessary to ensure non-cygwin apps can handle
> >>> CR/NL as expected. Therefor, CR and NL should be treated as the
> >>> same way in accept_input() if the data is sent to nat-pipe.
> >>
> >> The above block is fine.
> >>
> >>> Usually, when pseudo console is activated, the input data for non-
> >>> cygwin app is not treated by accept_input. However, accept_input()
> >>> handle the input data in pseudo console enabled mode, only in a
> >>> very short duration when pseudo console is about to setup, because
> >>> master::write() calls line_edit() in the pcon_start mode. If pseudo
> >>> console is disabled, accept_input() handles them, however usually
> >>> ICRNL flag is set, so line_edit() do this conversion. However, if
> >>> this flag is not set, the conversion added by this patch is needed
> >>> as well.
> >>
> >> This block I'm having a bit of trouble to follow.  Can you possibly
> >> reword to describe it in more orderly fashion?
> > 
> > What about:
> >    In the previous implementation, problems rarely occurred because
> >    accept_input() normally does not handle input for non-cygwin apps
> >    when the pseudo console is active. Under typical conditions, such
> >    input is snet to pseudo console directly by WriteFile(), so
>                ^^^^
> >    accept_input() is not involved and no onversion issues arise.
>                                             ^^^^^^^^^
> > 
> >    There is, however, a brief period during pseudo console initialization
> >    in which accept_input *does* handle the input. This happens because
> >    master::write() invokes line_edit() while in pcons_start mode. During
> >    this short window, the input is processed in pseudo-console-enabled
> >    mode, and the usual conversion behaviour may not apply.
> > 
> >    When the pseudo console is disabled, accept_input() always handles
> >    the input, and in most cases the ICRNL flag is set by shell, so
> >    line_edit() performs the CR->NL conversion. But if the flag is not
> >    set, this conversion does not occur. Therefore, the additional
> >    conversion introduced by this patch is required to ensure consistent
> >    behaviour in both cases.
> 
> Much better!  Please fix the minor typos indicated and it will LGTM.
> OK to push.
> 
> ..mark


-- 
Takashi Yano <[email protected]>