X11: WM_NAME is incorrectly set as UTF-8 and not UTF8_STRING

[FascinatedBox]

Your system information

• Steam client version (build number or date): 1714854927
• Distribution (e.g. Ubuntu): Ubuntu Jammy
• Opted into Steam client beta?: [Yes/No] Yes
• Have you checked for system updates?: [Yes/No] Yes
• Steam Logs: Not relevant to this issue
• GPU: Not relevant to this issue
• Display Manager: X11

Please describe your issue in as much detail as possible:

Using xprop on Steam shows, among other properties, the following:

_NET_WM_NAME(UTF8_STRING) = "Steam"
WM_NAME(UTF-8) = "Steam"

The first property, _NET_WM_NAME, is fine. However, the latter uses UTF-8 instead of UTF8_STRING. As a result, Xlib's Xutf8TextListToTextProperty returns -3 (XConverterNotFound). This is despite WM_LOCALE_NAME being set to "en_US.UTF-8".

jordansissel/xdotool#456