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Crash when changing window properties in threading thread #3719

@lapiscarrot

Description

@lapiscarrot

Environment:

Platform:		Windows-11-10.0.26200-SP0
System:			Windows
System Version:		10.0.26200
Processor:		AMD64 Family 26 Model 96 Stepping 0, AuthenticAMD	SSE2: Yes	AVX2: Yes	NEON: No
Architecture:		Bits: 64bit	Linkage: WindowsPE

Python:			CPython 3.14.2 (tags/v3.14.2:df79316, Dec  5 2025, 17:18:21) [MSC v.1944 64 bit (AMD64)]
GIL Enabled:		True
pygame version:		2.5.6
SDL versions:		Linked: 2.32.10	Compiled: 2.32.10
SDL Mixer versions:	Linked: 2.8.1	Compiled: 2.8.1
SDL Font versions:	Linked: 2.24.0	Compiled: 2.24.0
SDL Image versions:	Linked: 2.8.8	Compiled: 2.8.8
Freetype versions:	Linked: 2.11.1	Compiled: 2.11.1

Display Driver:		Display Not Initialized
Mixer Driver:		Mixer Not Initialized

Current behavior:

Program hangs indefinitely, on all threads running. There is no error message, and Ctrl+Shift+C doesn't work. In the test code given, the title remains as "a", and is never changed to "b".

Expected behavior:

The window's title should be able to be changed in a thread???

Steps to reproduce:

Make a thread using the threading module that changes a window's title, position, etc. and start it.

Test code

import pygame as pg
import threading

pg.init()

W = pg.Window(title='a')

def f():
    W.title = 'b'

thread = threading.Thread(target=f)
thread.start()

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