bug#3615: 23.0.94; (elisp)Local Variables: xrefs to nodes for buffer-local and frame-local vars

[Juanma Barranquero <lekktu@gmail.com>]

> Why deprecate frame-local variables?

There's a long thread in emacs-devel, titled "frame-local variables
weirdness", started on 2006-12-05. After many exchanges, you said:

"When frame-local variables were first implemented, there was no other
way to put frame-specific data in the mode line.  But now there is,
with :eval.

Since they are hardly used, and the original motive for them
no longer applies, we may as well delete the feature.

Would you like to do that?"

and Stefan answered:

"Sure.  I currently just marked it obsolete in the 22 branch (with a note in
NEWS), see patch below.  I'll change the pieces of code which make use of
that feature on the trunk.  If anybody wants to help out: feel free."

and then you said:

"I will delete them from the Lisp manual."

Basically, they are a source of subtle, obscure bugs; they do not
provide (almost) anything that cannot be done with
(set-)?frame-parameter, and after ten years or so of its
implementation they had all of four uses in the sources, all of them
trivial and trivially changed.

    Juanma