dynamic conpty loading

[Takashi Yano]

On Wed, 26 Nov 2025 19:50:07 +0100
Thomas Wolff wrote:
> 
> Am 26.11.2025 um 11:32 schrieb Takashi Yano via Cygwin:
> > On Fri, 21 Nov 2025 17:58:01 +0100
> > Thomas Wolff wrote:
> >
> >> Am 21.11.2025 um 17:46 schrieb Corinna Vinschen via Cygwin:
> >>> Hi Thomas,
> >>>
> >>> On Nov 21 16:46, Thomas Wolff via Cygwin wrote:
> >>>> Am 21.11.2025 um 11:04 schrieb Takashi Yano via Cygwin:
> >>>>> On Sun, 5 Oct 2025 10:15:55 +0200
> >>>>> Thomas Wolff wrote:
> >>>>>>>> The procedure seems to be:
> >>>>>>>> try LoadLibrary("conpty.dll"), (if not successful, fallback to
> >>>>>>>> GetModuleHandle("kernel32") instead) to retrieve GetProcAddress for
> >>>>>>>> CreatePseudoConsole, ResizePseudoConsole, ClosePseudoConsole, and
> >>>>>>>> then somehow (?) use those while calling CreateProcess.
> >>>>>>>> The latter is woven into the cygwin library and I don't think it's a
> >>>>>>>> good idea to clone that out of cygwin for a patched process creation
> >>>>>>>> in mintty.
> >>>>>>>>
> >>>>>>>> My question/suggestion:
> >>>>>>>> Can a cygwin mode switch to a selected conpty library instead of the
> >>>>>>>> default one please?
> >>> Where do you expect this conpty.dll to reside?
> >>>
> >>> If we do something like that, I would suggest to make sure that this
> >>> conpty.dll is in a well-defined place. /bin or /lib might be a good
> >>> idea. And if it exists in this defined place, it will be used by Cygwin.
> >>>
> >>> We can tweak the autoload mechanism to allow a primary DLL and a fallback
> >>> DLL, that drops the need to set the CYWIN env var.
> >>>
> >>> The mintty package could contain a post-install script, or some other
> >>> script in /bin to allow a user with admin rights downloading the latest
> >>> (or the most sensible) conpty.dll from MSFT.
> >>>
> >>> Would that make sense?
> >>>
> >>>
> >>> Corinna
> >>>
> >> That makes much sense, yes, thank you. /bin/conpty.dll would probably be
> >> a good place.
> > I checked the source of conpty.dll
> > https://github.com/microsoft/terminal/blob/main/src/winconpty/winconpty.cpp
> >
> > conpty.dll seems to launch OpenConsole.exe in the directory where
> > WindowsTerminal is installed.
> > However, BUILTIN\Users does not have permission to execute OpenConsole.exe.
> >
> > Do you have some idea how to solve this problem?
> > WindowsTerminal itself can launch OpenConsole.exe, so there should be
> > some solutions, I think.
> Did you install the nuget package? It can be extracted with zip, so you 
> can install OpenConsole as a normal program...
> I did not find a way, though, to invoke it explicitly so that it would 
> solve the pty interworking problems.

Thanks.

I've made an experimental patch against fhandler/pty.cc and
draft package named openconsole that installs official OpenConsole.exe
binary into /usr/bin.

I confirmed the patch with openconsole package enables the mouse
support for vim91 and neovim 0.8.0 (native windows binary) in
pseudo console.

Any comments and suggestions would be appreciated.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>
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