Cygwin: console: Fix issues of apps which open pty.

- After some recent changes for special keys handling break the
  apps which open pty (such as script command). If the app which
  opens pty is executed in console, the following issues occur.
    1) If the script command was started from non-cygwin shell
       (such as cmd.exe), another cygwin app started in pty slave
       cannot receive Ctrl-C.
    2) If non-cygwin app is executed in pty slave, the app which
       opened the pty (e.g. script command) crashes by Ctrl-C.
  This patch fixes these issues.

winsup/cygwin/fhandler.h

@@ -1921,7 +1921,7 @@ class fhandler_termios: public fhandler_base
   HANDLE& get_output_handle_nat () { return output_handle; }
   static process_sig_state process_sigs (char c, tty *ttyp,
 					 fhandler_termios *fh);
-  static bool process_stop_start (char c, tty *ttyp, bool on_ixany);
+  static bool process_stop_start (char c, tty *ttyp);
   line_edit_status line_edit (const char *rptr, size_t nread, termios&,
 			      ssize_t *bytes_read = NULL);
   void set_output_handle (HANDLE h) { output_handle = h; }

winsup/cygwin/fhandler_console.cc

@@ -189,7 +189,7 @@ void
 fhandler_console::cons_master_thread (handle_set_t *p, tty *ttyp)
 {
   termios &ti = ttyp->ti;
-  DWORD output_stopped_at = 0;
+  int processed_up_to = -1;
   while (con.owner == myself->pid)
     {
       DWORD total_read, n, i;
@@ -210,6 +210,7 @@ fhandler_console::cons_master_thread (handle_set_t *p, tty *ttyp)
 			     input_rec, INREC_SIZE, &total_read);
 	  break;
 	case WAIT_TIMEOUT:
+	  processed_up_to = -1;
 	case WAIT_SIGNALED:
 	case WAIT_CANCELED:
 	  break;
@@ -232,11 +233,10 @@ fhandler_console::cons_master_thread (handle_set_t *p, tty *ttyp)
 	      ttyp->kill_pgrp (SIGWINCH);
 	    }
 	}
-      for (i = 0; i < total_read; i++)
+      for (i = processed_up_to + 1; i < total_read; i++)
 	{
 	  wchar_t wc;
 	  char c;
-	  bool was_output_stopped;
 	  bool processed = false;
 	  switch (input_rec[i].EventType)
 	    {
@@ -256,14 +256,12 @@ fhandler_console::cons_master_thread (handle_set_t *p, tty *ttyp)
 		  ttyp->output_stopped = false;
 		  if (ti.c_lflag & NOFLSH)
 		    goto remove_record;
+		  processed_up_to = -1;
 		  goto skip_writeback;
 		default: /* not signalled */
 		  break;
 		}
-	      was_output_stopped = ttyp->output_stopped;
-	      processed = process_stop_start (c, ttyp, i > output_stopped_at);
-	      if (!was_output_stopped && ttyp->output_stopped)
-		output_stopped_at = i;
+	      processed = process_stop_start (c, ttyp);
 	      break;
 	    case WINDOW_BUFFER_SIZE_EVENT:
 	      SHORT y = con.dwWinSize.Y;
@@ -284,14 +282,16 @@ fhandler_console::cons_master_thread (handle_set_t *p, tty *ttyp)
 remove_record:
 	  if (processed)
 	    { /* Remove corresponding record. */
-	      memmove (input_rec + i, input_rec + i + 1,
-		       sizeof (INPUT_RECORD) * (total_read - i - 1));
+	      if (total_read > i + 1)
+		memmove (input_rec + i, input_rec + i + 1,
+			 sizeof (INPUT_RECORD) * (total_read - i - 1));
 	      total_read--;
 	      i--;
 	    }
 	}
+      processed_up_to = total_read - 1;
       if (total_read)
-	/* Write back input records other than interrupt. */
+	/* Writeback input records other than interrupt. */
 	WriteConsoleInputW (p->input_handle, input_rec, total_read, &n);
 skip_writeback:
       ReleaseMutex (p->input_mutex);

winsup/cygwin/fhandler_termios.cc

@@ -344,10 +344,12 @@ fhandler_termios::process_sigs (char c, tty* ttyp, fhandler_termios *fh)
 	      (myself->dwProcessId, false);
 	  if (resume_pid && fh && !fh->is_console ())
 	    {
+	      if (::cygheap->ctty && ::cygheap->ctty->is_console ())
+		init_console_handler (false);
 	      FreeConsole ();
 	      AttachConsole (p->dwProcessId);
 	    }
-	  if (fh && p == myself)
+	  if (fh && p == myself && being_debugged ())
 	    { /* Avoid deadlock in gdb on console. */
 	      fh->tcflush(TCIFLUSH);
 	      fh->release_input_mutex_if_necessary ();
@@ -372,6 +374,8 @@ fhandler_termios::process_sigs (char c, tty* ttyp, fhandler_termios *fh)
 	    {
 	      FreeConsole ();
 	      AttachConsole (resume_pid);
+	      if (::cygheap->ctty && ::cygheap->ctty->is_console ())
+		init_console_handler (true);
 	    }
 	}
       if (p && p->ctty == ttyp->ntty && p->pgid == pgid)
@@ -447,7 +451,7 @@ fhandler_termios::process_sigs (char c, tty* ttyp, fhandler_termios *fh)
       return signalled;
     }
 not_a_sig:
-  if (need_discard_input)
+  if ((ti.c_lflag & ISIG) && need_discard_input)
     {
       if (!(ti.c_lflag & NOFLSH) && fh)
 	{
@@ -462,7 +466,7 @@ not_a_sig:
 }
 
 bool
-fhandler_termios::process_stop_start (char c, tty *ttyp, bool on_ixany)
+fhandler_termios::process_stop_start (char c, tty *ttyp)
 {
   termios &ti = ttyp->ti;
   if (ti.c_iflag & IXON)
@@ -478,7 +482,7 @@ restart_output:
 	  ttyp->output_stopped = false;
 	  return true;
 	}
-      else if ((ti.c_iflag & IXANY) && ttyp->output_stopped && on_ixany)
+      else if ((ti.c_iflag & IXANY) && ttyp->output_stopped)
 	goto restart_output;
     }
   if ((ti.c_lflag & ICANON) && (ti.c_lflag & IEXTEN)
@@ -526,7 +530,7 @@ fhandler_termios::line_edit (const char *rptr, size_t nread, termios& ti,
 	default: /* Not signalled */
 	  break;
 	}
-      if (process_stop_start (c, get_ttyp (), true))
+      if (process_stop_start (c, get_ttyp ()))
 	continue;
       /* Check for special chars */
       if (c == '\r')

winsup/cygwin/fhandler_tty.cc

@@ -2301,7 +2301,7 @@ fhandler_pty_master::write (const void *ptr, size_t len)
 	      nlen--;
 	      i--;
 	    }
-	  process_stop_start (buf[i], get_ttyp (), true);
+	  process_stop_start (buf[i], get_ttyp ());
 	}
 
       DWORD n;