bug#66546: 30.0.50; save-buffer to write-protected file without backup fails

[Jens Schmidt]

Eli Zaretskii <eliz@gnu.org> writes:

> But I think I can guess what you wanted to say: you wanted to say that
> set-file-modes is called _only_ if set-file-extended-attributes fails,
> and it doesn't fail in this scenario.  Is that what you wanted to say?

Yes!  Thanks for guessing :-)

And I have been asking a related question implicitly in the previous
conversation, so here is it explicitly:

Using *only* the extended-attribute Elisp functions and objects, is
there currently a way to implement the equivalent of "chmod u+w FILE" in
Elisp?