bug#45197: Saving customizations makes ~/.config/emacs/init (no .el extension)

[tsuucat]

Subject says all.

How to reproduce:
1. $ cd /tmp
2. $ mkdir -p test-home/.config/emacs
3. $ cd test-home
4. $ HOME=$PWD emacs
5. M-x customize, edit something and Save for Future Sessions.
=> Wrote /tmp/test-home/.config/emacs/init

init (not init.el) is created.
This is because user-init-file is set to “/tmp/test-home/.config/emacs/init”.

Emacs manual doesn’t refer ~/.config/emacs/init so I think this is not intended.

Changing
     (lambda ()
       (expand-file-name
        “init"
        startup-init-directory))
to
     (lambda ()
       (expand-file-name
        “init.el"
        startup-init-directory))
in startup.el
maybe solve this (like early-init.el)?

--
tsuucat