bug#15539: [PATCH] Setting user-emacs-directory

[Paul Eggert]

Glenn Morris wrote:
> XDG_CONFIG_HOME
> is not an Emacs-specific variable, so changing it will impact other
> things that may be called from within Emacs.

True, but it should suffice for many use cases mentioned in Bug#15539. Of the 
cases mentioned here:

https://bugs.gnu.org/15539#66

XDG_HOME should suffice for most of issues mentioned. Not all: for example, 
overriding XDG_CONFIG_HOME overrides Gtk configuration, font configuration, and 
other settings covered by the XDG convention, whereas one might want to override 
just ~/.config/emacs. But it strikes me that this is often just as much of a 
feature as a drawback, since Gtk etc. configurations influence Emacs so much 
that they really ought to be saved/restored when one is thinking of 
saving/restoring Emacs settings.

One might have a situation where one wants to vary (or save) files traditionally 
kept in ~/.emacs.d/, and no other files. But it's also quite plausible that one 
will want some of those files and not others, just as one might want 
~/.config/emacs and ~/.config/fontconfig but not ~/.config/gtk-3.0. And it's 
unlikely that a single option will have all the fine-grained control that one 
would need for all these situations. Instead, it's probably better just to 
suggest to people that they set up $HOME (or perhaps $XDG_CONFIG_HOME) to point 
to a directory full of configurations that are just they way they like it.