Cygwin: console: Store console mode only when console is opened

... and restore it when app exits. The commit 0bfd91d has a bug
that the console mode is stored into the shared memory when both:
  (1) cygwin process is started from non-cygwin process.
  (2) cygwin process started from non-cygwin process exits.
(1) is intended, but (2) is not. Due to (2), the stored console mode
is unexpectedly broken when the cygwin process exits. Then the mode
restored will be not as expected. This causes undesired console mode
in the use case that cygwin and non-cygwin apps are mixed.

With this patch, the console mode will stored only in the case (1).
This is done by putting the code, which stores the console mode, into
fhandler_console::open() rather than fhandler_console::set_input_mode()
and fhandler_console::set_output_mode().

Fixes: 0bfd91d ("Cygwin: console: tty::restore really restores the previous mode")
Reported-by: Johannes Schindelin <[email protected]>
Signed-off-by: Takashi Yano <[email protected]>
(cherry picked from commit 09ae9f6)

Author: tyan0

winsup/cygwin/fhandler/console.cc

@@ -771,6 +771,8 @@ fhandler_console::setup ()
       con.disable_master_thread = true;
       con.master_thread_suspended = false;
       con.num_processed = 0;
+      con.curr_input_mode = tty::restore;
+      con.curr_output_mode = tty::restore;
     }
 }
 
@@ -849,11 +851,6 @@ fhandler_console::set_input_mode (tty::cons_mode m, const termios *t,
 	flags |= ENABLE_PROCESSED_INPUT;
       break;
     }
-  if (con.curr_input_mode != tty::cygwin && m == tty::cygwin)
-    {
-      prev_input_mode_backup = con.prev_input_mode;
-      con.prev_input_mode = oflags;
-    }
   con.curr_input_mode = m;
   SetConsoleMode (p->input_handle, flags);
   if (!(oflags & ENABLE_VIRTUAL_TERMINAL_INPUT)
@@ -893,11 +890,6 @@ fhandler_console::set_output_mode (tty::cons_mode m, const termios *t,
 	flags |= DISABLE_NEWLINE_AUTO_RETURN;
       break;
     }
-  if (con.curr_output_mode != tty::cygwin && m == tty::cygwin)
-    {
-      prev_output_mode_backup = con.prev_output_mode;
-      GetConsoleMode (p->output_handle, &con.prev_output_mode);
-    }
   con.curr_output_mode = m;
   acquire_attach_mutex (mutex_timeout);
   DWORD resume_pid = attach_console (con.owner);
@@ -1836,6 +1828,12 @@ fhandler_console::open (int flags, mode_t)
   handle_set.output_handle = h;
   release_output_mutex ();
 
+  if (con.owner == GetCurrentProcessId ())
+    {
+      GetConsoleMode (get_handle (), &con.prev_input_mode);
+      GetConsoleMode (get_output_handle (), &con.prev_output_mode);
+    }
+
   wpbuf.init ();
 
   handle_set.input_mutex = input_mutex;
@@ -1881,6 +1879,19 @@ fhandler_console::open (int flags, mode_t)
 	setenv ("TERM", "cygwin", 1);
     }
 
+  if (con.curr_input_mode != tty::cygwin)
+    {
+      prev_input_mode_backup = con.prev_input_mode;
+      GetConsoleMode (get_handle (), &con.prev_input_mode);
+      set_input_mode (tty::cygwin, &get_ttyp ()->ti, &handle_set);
+    }
+  if (con.curr_output_mode != tty::cygwin)
+    {
+      prev_output_mode_backup = con.prev_output_mode;
+      GetConsoleMode (get_output_handle (), &con.prev_output_mode);
+      set_output_mode (tty::cygwin, &get_ttyp ()->ti, &handle_set);
+    }
+
   debug_printf ("opened conin$ %p, conout$ %p", get_handle (),
 		get_output_handle ());
 
@@ -4720,7 +4731,7 @@ fhandler_console::cons_mode_on_close (handle_set_t *p)
   NTSTATUS status =
     NtQueryInformationProcess (GetCurrentProcess (), ProcessBasicInformation,
 			       &pbi, sizeof (pbi), NULL);
-  if (NT_SUCCESS (status)
+  if (NT_SUCCESS (status) && cygwin_pid (con.owner)
       && !process_alive ((DWORD) pbi.InheritedFromUniqueProcessId))
     /* Execed from normal cygwin process and the parent has been exited. */
     return tty::cygwin;