bug#33255: 27.0.50; expand-file-name: default directory expanded twice if relative

[Paul Eggert]

> I think a non-absolute HOME is a user error.
> Eg cd $HOME may then not be idempotent.
That's true. However, POSIX says that sh treats ~/foo like $HOME/foo 
even when HOME is not absolute, and it's better if Emacs is consistent 
with POSIX as much as possible within the Emacs constraint that 
expand-file-name must expand to an absolute file name. So I implemented 
something along the line of Noam's suggestion by installing the attached 
patch into master; this should fix the bug originally reported.

Unlike Noam's suggestion, this patch causes Emacs to look at the current 
value of HOME, not the value HOME had when Emacs started up, as that 
corresponds more closely to POSIX sh.

0001-Act-like-POSIX-sh-if-HOME-is-relative.patch
Description: Text Data