Fixed the NoConsoleScreenBuffer error that appeared on some 64bit Python versions.

Author: jonathanslenders

prompt_toolkit/terminal/win32_output.py

@@ -141,9 +141,31 @@ def get_win32_screen_buffer_info(self):
  """
  Return Screen buffer info.
  """
+ # NOTE: We don't call the `GetConsoleScreenBufferInfo` API through
+ # `self._winapi`. Doing so causes Python to crash on certain 64bit
+ # Python versions. (Reproduced with 64bit Python 2.7.6, on Windows
+ # 10). It is not clear why. Possibly, it has to do with passing
+ # these objects as an argument, or through *args.
+
+ # The Python documentation contains the following - possibly related - warning:
+ # ctypes does not support passing unions or structures with
+ # bit-fields to functions by value. While this may work on 32-bit
+ # x86, it's not guaranteed by the library to work in the general
+ # case. Unions and structures with bit-fields should always be
+ # passed to functions by pointer.
+
+ # Also see:
+ # - https://github.com/ipython/ipython/issues/10070
+ # - https://github.com/jonathanslenders/python-prompt-toolkit/issues/406
+ # - https://github.com/jonathanslenders/python-prompt-toolkit/issues/86
+
+ self.flush()
  sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
- success = self._winapi(windll.kernel32.GetConsoleScreenBufferInfo,
- self.hconsole, byref(sbinfo))
+ success = windll.kernel32.GetConsoleScreenBufferInfo(self.hconsole, byref(sbinfo))
+
+ # success = self._winapi(windll.kernel32.GetConsoleScreenBufferInfo,
+ # self.hconsole, byref(sbinfo))
+
  if success:
  return sbinfo
  else: