Do not treat ~nosuchuser as an absolute file name

Derived from Ken Brown’s patch (Bug#36502#97).
* doc/lispref/files.texi (Relative File Names):
* etc/NEWS: Document this.
* src/fileio.c (user_homedir): New function.
(Fexpand_file_name, file_name_absolute_p): Use it.
(search_embedded_absfilename): Simplify via file_name_absolute_p.
* test/src/fileio-tests.el (fileio-tests--no-such-user): New test.

1 files changed, 3 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 5313270411c..08f0e654f7f 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1815,6 +1815,9 @@ relative to the 'default-directory' of the current buffer.  We recommend
 always setting "$HOME" to an absolute file name, so that its meaning is
 independent of where Emacs was started.
 
+** file-name-absolute-p no longer considers "~foo" to be an absolute
+file name if there is no user named "foo".
+
 ** The FILENAME argument to 'file-name-base' is now mandatory and no
 longer defaults to 'buffer-file-name'.