Emacs local variables sections in files; time-stamping

[Glenn Morris]

Hi,

I'm not sure if I should be reporting this to gnulib or to the various
upstreams from which the relevant files derive; but it seems to be a
common feature...

We have various files in Emacs that are synced from gnulib now.
Several of them:

  compile, config.guess, config.sub, depcomp, doc/misc/texinfo.tex
  install-sh, missing, mkinstalldirs

contain stuff like this:

    # Local Variables:
    # mode: shell-script
    # sh-indentation: 2
    # eval: (add-hook 'write-file-hooks 'time-stamp)
    # time-stamp-start: "scriptversion="
    # time-stamp-format: "%:y-%02m-%02d.%02H"
    # time-stamp-time-zone: "UTC"
    # time-stamp-end: "; # UTC"
    # End:

Firstly, a minor point. write-file-hooks is obsolete since Emacs 22.1,
replaced by write-file-functions. (Actually, the Emacs documentation
suggests using before-save-hook for time-stamping.)

My main point is, having this stanza in the files is extremely
annoying. Because `eval' is potentially risky, every time I open one
of these files in Emacs, I get a prompt:
    
    The local variables list in config.sub
    contains values that may not be safe (*).
    
    Do you want to apply it? [...]
      * eval : (add-hook (quote write-file-hooks) (quote time-stamp))

I generally answer `n' anyway, because I don't want to accidentally
bump the time-stamp.

Is it really necessary to have this setting in the files?