https://gitlab.com/dogtail/dogtail/-/merge_requests/40

commit 887d421c276fd5bc61b8482c985463687598ec4e
Author: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date:   Sun Oct 27 00:24:53 2024 +0200

    get_current_x_window_position: Support running without a wm
    
    Tests are typically run without a wm, in which case there is no
    _NET_ACTIVE_WINDOW properly, but the windows will be at 0,0.

diff --git a/dogtail/utils.py b/dogtail/utils.py
index d6cac36..d6b2658 100644
--- a/dogtail/utils.py
+++ b/dogtail/utils.py
@@ -504,7 +504,11 @@ def get_current_x_window_position():
     
     d = display.Display()
     root = d.screen().root
-    window_id = root.get_full_property(d.intern_atom('_NET_ACTIVE_WINDOW'), X.AnyPropertyType).value[0]
+    prop = root.get_full_property(d.intern_atom('_NET_ACTIVE_WINDOW'), X.AnyPropertyType)
+    if prop is None:
+        return 0, 0
+
+    window_id = prop.value[0]
     window = d.create_resource_object('window', window_id)
 
     try:
