[newlib-cygwin/cygwin-3_3-branch] Cygwin: console: Maintain ENABLE_(INSERT|QUICK_EDIT)_MODE flags.

[Takashi Yano]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=a6f441c8d22a38dd8b8bee1190fa391abde57522

commit a6f441c8d22a38dd8b8bee1190fa391abde57522
Author: Mitchell Hentges <mhentges@mozilla.com>
Date:   Thu Feb 10 10:38:08 2022 -0500

    Cygwin: console: Maintain ENABLE_(INSERT|QUICK_EDIT)_MODE flags.
    
    - Currently, ENABLE_INSERT_MODE and ENABLE_QUICK_EDIT_MODE are cleared
      if cygwin is started in console. These flags will not be recovered
      even when exiting from cygwin. Also note that if ENABLE_EXTENDED_FLAGS
      is once unset, then the flag ENABLE_QUICK_EDIT_MODE it's associated
      with will no longer be preserved. Unfortunately, we're accidentally
      stepping on this in fhandler_console::set_input_mode().
    
      This patch solves this by carrying forward these flags in the place
      where it had been ignoring them. Since the previous behaviour of
      leaving these flags unset would essentially maintain their existing
      state, adding the carry-over of the flags now should not alter console
      behaviour.

Diff:
---
 winsup/cygwin/fhandler_console.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 23421dbfa..17452cd27 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -458,16 +458,18 @@ void
 fhandler_console::set_input_mode (tty::cons_mode m, const termios *t,
 				  const handle_set_t *p)
 {
-  DWORD flags = 0, oflags;
+  DWORD oflags;
   WaitForSingleObject (p->input_mutex, mutex_timeout);
   GetConsoleMode (p->input_handle, &oflags);
+  DWORD flags = oflags
+    & (ENABLE_EXTENDED_FLAGS | ENABLE_INSERT_MODE | ENABLE_QUICK_EDIT_MODE);
   switch (m)
     {
     case tty::restore:
-      flags = ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
+      flags |= ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
       break;
     case tty::cygwin:
-      flags = ENABLE_WINDOW_INPUT;
+      flags |= ENABLE_WINDOW_INPUT;
       if (wincap.has_con_24bit_colors () && !con_is_legacy)
 	flags |= ENABLE_VIRTUAL_TERMINAL_INPUT;
       else