[newlib-cygwin] Cygwin: pty: Make system_printf() work after closing pty slave.

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=0365031ce1347600d854a23f30f1355745a1765c

commit 0365031ce1347600d854a23f30f1355745a1765c
Author: Takashi Yano via Cygwin-patches <cygwin-patches@cygwin.com>
Date:   Tue May 19 20:35:59 2020 +0900

    Cygwin: pty: Make system_printf() work after closing pty slave.
    
    - Current pty cannot show system_printf() output after closing pty
      slave. This patch fixes the issue.

Diff:
---
 winsup/cygwin/fhandler_tty.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 5a1bcd3ce..02b78cd2c 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -948,6 +948,10 @@ fhandler_pty_slave::open (int flags, mode_t)
       init_console_handler (true);
     }
 
+  get_ttyp ()->pcon_pid = 0;
+  get_ttyp ()->switch_to_pcon_in = false;
+  get_ttyp ()->switch_to_pcon_out = false;
+
   set_open_status ();
   return 1;
 
@@ -1008,6 +1012,7 @@ fhandler_pty_slave::close ()
     termios_printf ("CloseHandle (output_mutex<%p>), %E", output_mutex);
   if (pcon_attached_to == get_minor ())
     get_ttyp ()->num_pcon_attached_slaves --;
+  set_switch_to_pcon (2); /* Make system_printf() work after close. */
   return 0;
 }