Core dumps in redisplay.

[David Kastrup <dak@gnu.org>]

Hello, in keyboard.c there is the following code:

DEFUN ("top-level", Ftop_level, Stop_level, 0, 0, "",
       doc: /* Exit all recursive editing levels.  */)
     ()
{
#ifdef HAVE_X_WINDOWS
  if (display_hourglass_p)
    cancel_hourglass ();
#endif

  /* Unblock input if we enter with input blocked.  This may happen if
     redisplay traps e.g. during tool-bar update with input blocked.  */
  while (INPUT_BLOCKED_P)
    UNBLOCK_INPUT;

  return Fthrow (Qtop_level, Qnil);
}

This approach of unblocking input appears completely useless to me,
since unwinding the stack includes restoration of
interrupt_input_blocked.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum