[PATCH] Cygwin: pty: Introduce disable_pcon in environment CYGWIN.

[Jon Turney]

On 20/01/2020 12:41, Takashi Yano wrote:
> Hi Corinna,
> 
> On Mon, 20 Jan 2020 11:06:46 +0100
> Corinna Vinschen wrote:
>> On Jan 20 11:50, Takashi Yano wrote:
>>> - For programs which does not work properly with pseudo console,
>>>    disable_pcon in environment CYGWIN is introduced. If disable_pcon
>>>    is set, pseudo console support is disabled.
>> Oh well, do we really need that?
> 
> This is, for example, needed to solve the issue reported in
> https://www.cygwin.com/ml/cygwin/2020-01/msg00147.html.
> 
> I looked into this problem, and found that cgdb read output of
> gdb from pty master and write it to ncurses. The output from
> pty master includes a lot of escape sequences which are generated
> by pseudo console, however, ncurses does not pass-through them
> and shows garbages. This is the cause of that issue.
> 
> cgdb is the only program do such things so far, however, there
> may be more programs which do not expect escape sequences read
> from pty.
> 
> There is no way to control pseudo console not to generate
> escape sequences, therefore, I proposed this patch.
> 

I think this may actually be an issue with cgdb being old.

The latest gdb enables "output styling" using ANSI escape sequences by 
default, but our cgdb can't handle them?

See: https://github.com/cgdb/cgdb/issues/211