Cygwin: console: Change timing of set/unset xterm compatible mode.cygwin-3_1_3-release

- If two cygwin programs are executed simultaneousley with pipes
  in cmd.exe, xterm compatible mode is accidentally disabled by
  the process which ends first. After that, escape sequences are
  not handled correctly in the other app. This is the problem 2
  reported in https://cygwin.com/ml/cygwin/2020-02/msg00116.html.
  This patch fixes the issue. This patch also fixes the problem 3.
  For these issues, the timing of setting and unsetting xterm
  compatible mode is changed. For read, xterm compatible mode is
  enabled only within read() or select() functions. For write, it
  is enabled every time write() is called, and restored on close().

1 files changed, 31 insertions, 1 deletions

diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc
index b06441c77..f3e3e4482 100644
--- a/winsup/cygwin/select.cc
+++ b/winsup/cygwin/select.cc
@@ -1075,19 +1075,49 @@ verify_console (select_record *me, fd_set *rfds, fd_set *wfds,
   return peek_console (me, true);
 }
 
+static int
+console_startup (select_record *me, select_stuff *stuff)
+{
+  select_record *s = stuff->start.next;
+  if (wincap.has_con_24bit_colors ())
+    {
+      DWORD dwMode;
+      GetConsoleMode (s->h, &dwMode);
+      /* Enable xterm compatible mode in input */
+      dwMode |= ENABLE_VIRTUAL_TERMINAL_INPUT;
+      SetConsoleMode (s->h, dwMode);
+    }
+  return 1;
+}
+
+static void
+console_cleanup (select_record *me, select_stuff *stuff)
+{
+  select_record *s = stuff->start.next;
+  if (wincap.has_con_24bit_colors ())
+    {
+      DWORD dwMode;
+      GetConsoleMode (s->h, &dwMode);
+      /* Disable xterm compatible mode in input */
+      dwMode &= ~ENABLE_VIRTUAL_TERMINAL_INPUT;
+      SetConsoleMode (s->h, dwMode);
+    }
+}
+
 select_record *
 fhandler_console::select_read (select_stuff *ss)
 {
   select_record *s = ss->start.next;
   if (!s->startup)
     {
-      s->startup = no_startup;
+      s->startup = console_startup;
       s->verify = verify_console;
       set_cursor_maybe ();
     }
 
   s->peek = peek_console;
   s->h = get_handle ();
+  s->cleanup = console_cleanup;
   s->read_selected = true;
   s->read_ready = input_ready || get_cons_readahead_valid ();
   return s;