win32process.GetWindowThreadProcessId returning [0, 0] when ctypes.windll.user32.GetWindowThreadProcessId works fine

[huntfx]

Expected behavior and actual behavior

I've found a case where pywin32 fails to get a process ID when ctypes manages.
I've been running this code for 6+ years and have never seen it happen before, so I'm afraid the only way I know how to reproduce this is with Helldivers 2.

Passing the window handle of Helldivers 2 to win32process.GetWindowThreadProcessId to get its process ID will return [0, 0], but with ctypes.windll.user32.GetWindowThreadProcessId it returns the correct process ID.

For any other process these two values are always the same.

Steps to reproduce the problem

>>> def get_pid_ctypes(hwnd):
...     process_id = ctypes.c_ulong()
...     ctypes.windll.user32.GetWindowThreadProcessId(hwnd, ctypes.byref(process_id))
...     return process_id.value

>>> def get_pid_pywin32(hwnd):
...     return win32process.GetWindowThreadProcessId(hwnd)[1]

>>> hwnd = win32gui.FindWindow(None, 'HELLDIVERS™ 2')
>>> hwnd
5245634 
>>> get_pid_ctypes(hwnd)
210628 
>>> get_pid_pywin32(hwnd)
0

1. Load Helldivers 2
2. Get its window handle
3. Attempt to get the PID via win32process.GetWindowThreadProcessId
4. It returns [0, 0]

For the sake of linking issues, I created huntfx/MouseTracks#65 on my own project before finding that the ctypes method worked.

System information

Python version and distribution:

Python 3.7.9
Python 3.11.8

pywin32 version:

300 for 3.7
308 for 3.11

Windows Version:

10.0.19045 Build 19045

DLL locations:

C:\Users\Peter\AppData\Roaming\Python\Python311\site-packages\pywin32_system32\pywintypes311.dll
C:\Users\Peter\AppData\Roaming\Python\Python311\site-packages\pywin32_system32\pythoncom311.dll