Re: [PATCH] Cygwin: pty: detect pcon-backed pty for non-Cygwin-spawned children

On Thu, 28 May 2026 15:48:24 +0200 (CEST)
Johannes Schindelin wrote:
> Hi Takashi,
> 
> On Tue, 5 May 2026, Takashi Yano wrote:
> 
> > On Thu, 30 Apr 2026 15:04:04 +0000
> > "Johannes Schindelin via GitGitGadget" wrote:
> > > From: Johannes Schindelin <[email protected]>
> > > 
> > > diff --git a/winsup/cygwin/dtable.cc b/winsup/cygwin/dtable.cc
> > > index 7303f7eac..ce29f4608 100644
> > > --- a/winsup/cygwin/dtable.cc
> > > +++ b/winsup/cygwin/dtable.cc
> > > @@ -327,7 +327,17 @@ dtable::init_std_file_from_handle (int fd, HANDLE handle)
> > >  	dev.parse (myself->ctty);
> > >        else
> > >  	{
> > > -	  dev.parse (FH_CONSOLE);
> > > +	  /* Check whether the inherited console is actually a pseudo
> > > +	     console bridging a pty.  This happens when our non-Cygwin
> > > +	     parent was itself spawned by a Cygwin process from a pty
> > > +	     (e.g. bash spawning git.exe which then spawns vim).  In
> > > +	     that case, connect to the pty slave instead of treating
> > > +	     the handle as a real console. */
> > > +	  int pcon_minor = cygwin_shared->tty.find_pcon_pty ();
> > > +	  if (pcon_minor >= 0)
> > > +	    dev.parse (FHDEV (DEV_PTYS_MAJOR, pcon_minor));
> > > +	  else
> > > +	    dev.parse (FH_CONSOLE);
> > >  	  CloseHandle (handle);
> > >  	  handle = INVALID_HANDLE_VALUE;
> > 
> > The lines:
> > CloseHandle (handle);
> > handle = INVALID_HANDLE_VALUE;
> > are dropped in master branch. Do you think that these two lines
> > are necessary for this patch when applying this patch to cygwin
> > master branch?
> 
> Those two lines are not necessary, all added code ignores the handle
> entirely.

OK. I think this patch is not a bug fix but a behavioral change,
so it should go only to the master branch. What do you think?

If so, the patch does not apply to master branch due to these
two lines. Could you please update the patch for master branch?

In addition, I would appreciate it if you could consider incorporating
the two additional patches I posted earlier.

-- 
Takashi Yano <[email protected]>