Rémi Bernon (@rbernon) commented about dlls/win32u/input.c:
{ user_driver->pSetCapture( hwnd, gui_flags );
if (!hwnd)
clip_fullscreen_window( NtUserGetForegroundWindow(), FALSE );
I'm not sure we need to restore the fullscreen clipping here, if the application uses SetCapture, maybe we can rely on it being called later when mouse is clicked?