Use XDG conventions more consistently

Fit in better with the XDG conventions.
Something like this was suggested in 2008 (Bug#583)
and the XDG conventions seem to have settled down by now.
* doc/emacs/custom.texi (Init File, Init Syntax, Find Init):
* doc/lispref/files.texi (Standard File Names):
* doc/lispref/os.texi (Init File):
* doc/misc/url.texi (Customization):
* etc/NEWS:
Adjust accordingly.
* lisp/startup.el (startup--load-user-init-file):
If init-file-name is nil, do not load from it; instead
just use the alt-file.
(find-init-path): Remove; no longer used.
(command-line): Don't check twice for XDG.
Look at XDG_CONFIG_HOME instead of assuming it's ~/.config.
Prefer XDG configuration if it exists; the user can disable
this by setting XDG_CONFIG_HOME to some other place.
* lisp/subr.el (user-emacs-directory):
Prefer XDG configuration if it exists.

2 files changed, 8 insertions, 4 deletions

diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index 6be5a528372..d53fed4ee87 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -2822,8 +2822,9 @@ filter out a directory named @file{foo.elc}.
 name for a particular use---typically, to hold configuration data
 specified by the current user.  Usually, such files should be located
 in the directory specified by @code{user-emacs-directory}, which is
-@file{~/.emacs.d} by default (@pxref{Init File}).  For example, abbrev
-definitions are stored by default in @file{~/.emacs.d/abbrev_defs}.
+@file{~/.config/emacs} or @file{~/.emacs.d} by default (@pxref{Init
+File}).  For example, abbrev definitions are stored by default in
+@file{~/.config/emacs/abbrev_defs} or @file{~/.emacs.d/abbrev_defs}.
 The easiest way to specify such a file name is to use the function
 @code{locate-user-emacs-file}.
 
diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index dd80b04ad83..df212569087 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -473,8 +473,11 @@ the value refers to the corresponding source file.
 @end defvar
 
 @defvar user-emacs-directory
-This variable holds the name of the @file{.emacs.d} directory.  It is
-@file{~/.emacs.d} on all platforms but MS-DOS.
+This variable holds the name of the Emacs default directory.
+It is @file{@var{xdghome}/emacs/} if that directory exists, otherwise
+@file{~/.emacs.d/} on all platforms but MS-DOS.  Here, @var{xdghome}
+stands for the value of the environment variable @env{XDG_CONFIG_HOME}
+if that variable is set, and for @file{~/.config} otherwise.
 @end defvar
 
 @node Terminal-Specific