pty issue causes 'screen' to hang when run from mintty as detached

Mon Jun 17 14:01:00 GMT 2013

On Mon, Jun 17, 2013 at 06:08:27AM -0400, Andrew Schulman wrote:
>> > Do we have any idea whether the problem is with mintty or with screen?
>>>> I observed the same behaviour as the OP, but also reproduced it in
>> rxvt and xterm, so not a mintty issue. Since it works in a console,
>> the Cygwin pty layer has to be the main suspect, unless screen has
>> specfic code for Cygwin consoles or ptys?
>>I don't think so, but there's one big, crufty old patch that I had to use to get
>screen to run a few years ago.
>>The version of screen that we're using now in Cygwin, 4.0.3, is about 8 years
>old. There haven't been any official new releases since then, but development
>has continued and there have been a lot of improvements. I'm in the process of
>building an updated package from the latest git, and that version appears not to
>need any of the patches I used to have to use to get screen to compile and run
>in Cygwin.
>>So, I suggest that we wait until the new screen test release comes out, within a
>few days, and see if that fixes the problem.

I looked at this briefly over the weekend and saw a problem in Cygwin's
pty handling code. I don't know exactly what the problem is yet but there
is something not quite right there. Something is closing a windows handle
and that's causing a SIGHUP to be sent to the pty owner. That's not right.
I'll fix this problem eventually but it will be interesting to see if a
newer screen behaves any better.
cgf
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