Esme Povirk (@madewokherd) commented about dlls/comdlg32/navbar.c:
hwnd, 0, COMDLG32_hInstance, NULL); SetWindowSubclass(info->background_hwnd, NAVBAR_BACKGROUND_SubclassProc, 0, (DWORD_PTR)info);
- info->overflow_hwnd = CreateWindowExW(0, WC_BUTTONW, NULL,
For accessibility it'd be good to give this button a title.