Pseudo console support in PTY

Thomas Wolff
Wed Apr 3 11:33:00 GMT 2019

On 03.04.2019 10:02, Corinna Vinschen wrote:
> On Apr  3 09:55, Thomas Wolff wrote:
>> Am 03.04.2019 um 09:27 schrieb Corinna Vinschen:
>>> On Apr  3 09:18, Thomas Wolff wrote:
>>>> Am 02.04.2019 um 19:50 schrieb Corinna Vinschen:
>>>>> On Apr  2 19:16, Thomas Wolff wrote:
>>>>>> Am 02.04.2019 um 13:02 schrieb Corinna Vinschen:
>>>>>>> Hi Takashi,
>>>>>>> On Mar 30 22:08, Takashi Yano wrote:
>>>>>>>> Patch 0003: Support pseudo console in PTY. With this patch,
>>>>>>>>       native console applications can work in PTY such as mintty,
>>>>>>>>       ssh, gnu screen or tmux.
>>>>>> I've now tried your patched binaries on two systems. On one they don't run,
>>>>>> on the other I saw no noticeable effect, particularly no impact on the
>>>>>> pty/console interoperability...
>>>>> Try starting cmd from your shell in mintty and do some native stuff.
>>>> I've now self-compiled cygwin dll on a third system and can run a cygwin
>>>> console.
>>>> But the build process did not generate the cygwin-console-helper, maybe
>>>> that's the reason why mintty does not start?
>> Can you give a hint that enables me to test the patch?
>>>>> You'll notice two differences:
>>>>> - cmd history works
>>>> In the cygwin console, it does not, echos the cursor-up escape sequence
>>> Oh, right, ...
>>>> instead. See my previous comment that I think ConPTY should only be applied
>>>> if running at a pty. (And for other reasons only when starting a non-cygwin
>>>> app.)
>>> but you got that wrong.  The conpty stuff *is* only applied for ptys.
>> So cygwin running as cygwin console still sets up a pty?
> Still?  It never did.  Call tty in a console and you get /dev/consX.
Misunderstanding, didn't mean "still", sorry.
> The ConPTY stuff only runs if the application requests a pty.
OK, but I think it should additionally be restricted to running 
non-cygwin apps.

By the way, when I previously reported the patch to have no effect, that 
was on a Windows 7 system, so of course it couldn't, sorry :/
Still failing to test the patch in mintty on Windows 10...

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