[PATCH] Cygwin: console: Retain ENABLE_VIRTUAL_TERMIANL_PROCESSING flag.

[Takashi Yano <takashi.yano@nifty.ne.jp>]

- Currently, ENABLE_VIRTUAL_TERMINAL_PROCESSING flag is disabled
  unconditionally when exiting from cygwin. This causes ANSI escape
  sequence disabled in Windows Terminal where it is enables by
  default. This patch retains that flag if it is originally enabled.
---
 winsup/cygwin/fhandler.h          | 1 +
 winsup/cygwin/fhandler_console.cc | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index dfad07f72..d7c358e7f 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -2022,6 +2022,7 @@ class dev_console
 {
   pid_t owner;
   bool is_legacy;
+  bool orig_virtual_terminal_processing_mode;
 
   WORD default_color, underline_color, dim_color;
 
diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 52239c2f9..12c2c4f12 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -597,6 +597,8 @@ fhandler_console::set_output_mode (tty::cons_mode m, const termios *t,
 				   const handle_set_t *p)
 {
   DWORD flags = ENABLE_PROCESSED_OUTPUT | ENABLE_WRAP_AT_EOL_OUTPUT;
+  if (con.orig_virtual_terminal_processing_mode)
+    flags |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
   WaitForSingleObject (p->output_mutex, mutex_timeout);
   switch (m)
     {
@@ -1505,6 +1507,8 @@ fhandler_console::open (int flags, mode_t)
       /* Check xterm compatible mode in output */
       acquire_attach_mutex (mutex_timeout);
       GetConsoleMode (get_output_handle (), &dwMode);
+      con.orig_virtual_terminal_processing_mode =
+	!!(dwMode & ENABLE_VIRTUAL_TERMINAL_PROCESSING);
       if (!SetConsoleMode (get_output_handle (),
 			   dwMode | ENABLE_VIRTUAL_TERMINAL_PROCESSING))
 	is_legacy = true;
-- 
2.36.1