Eli Zaretskii wrote:
> I myself don't have time to work on this, and don't consider myself
> enough of an expert on the XDG stuff anyway.  So I will wait for a
> couple of weeks for someone to pick up the gauntlet

I'll give it a whirl. Proposed patch attached. This reflects the comments so 
far, except that it prefers the new (XDG-style) directory if it exists, as that 
gives the user a simple escape hatch. They can set XDG_CONFIG_DIR to /nowhere to 
go back to the old way, as an emergency fix to get Emacs up and running well 
enough to fix their configuration. In practice it appears that XDG_CONFIG_DIR is 
rarely if ever set, so this should be adequate as an escape hatch.