[newlib-cygwin] Cygwin: console: Add code to restore console mode on close.

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=783eaa888feaf4f76df3d3449e29aa20aa78c802

commit 783eaa888feaf4f76df3d3449e29aa20aa78c802
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date:   Thu Jan 2 22:17:16 2020 +0900

    Cygwin: console: Add code to restore console mode on close.
    
    - The console with 24bit color support has a problem that console
      mode is changed if cygwin process is executed in cmd.exe which
      started in cygwin shell. For example, cursor keys become not
      working if bash -> cmd -> true are executed in this order.
      This patch fixes the issue.

Diff:
---
 winsup/cygwin/fhandler_console.cc | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 337331b..b3f2cb6 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -53,6 +53,9 @@ fhandler_console::console_state NO_COPY *fhandler_console::shared_console_info;
 
 bool NO_COPY fhandler_console::invisible_console;
 
+static DWORD orig_conin_mode = (DWORD) -1;
+static DWORD orig_conout_mode = (DWORD) -1;
+
 static void
 beep ()
 {
@@ -1010,6 +1013,11 @@ fhandler_console::open (int flags, mode_t)
   get_ttyp ()->rstcons (false);
   set_open_status ();
 
+  if (orig_conin_mode == (DWORD) -1)
+    GetConsoleMode (get_handle (), &orig_conin_mode);
+  if (orig_conout_mode == (DWORD) -1)
+    GetConsoleMode (get_output_handle (), &orig_conout_mode);
+
   if (getpid () == con.owner && wincap.has_con_24bit_colors ())
     {
       DWORD dwMode;
@@ -1079,6 +1087,19 @@ fhandler_console::close ()
       SetConsoleMode (get_output_handle (), dwMode);
     }
 
+  /* Restore console mode if this is the last closure. */
+  OBJECT_BASIC_INFORMATION obi;
+  NTSTATUS status;
+  status = NtQueryObject (get_handle (), ObjectBasicInformation,
+			  &obi, sizeof obi, NULL);
+  if (NT_SUCCESS (status) && obi.HandleCount == 1)
+    {
+      if (orig_conin_mode != (DWORD) -1)
+	SetConsoleMode (get_handle (), orig_conin_mode);
+      if (orig_conout_mode != (DWORD) -1)
+	SetConsoleMode (get_handle (), orig_conout_mode);
+    }
+
   CloseHandle (get_handle ());
   CloseHandle (get_output_handle ());