Change `customize-save-variable' to work under "emacs -Q"?

[Stephen J. Turnbull]

Lars Magne Ingebrigtsen writes:

 > If you run "emacs -Q", and you have a piece of code that calls
 > `customize-save-variable', it will error out, saying that it won't
 > overwrite the conf.

If that's not the appropriate thing to do, isn't the piece of code
abusing `customize-save-variable'?  Customize itself is carefully
designed so that the user has the choice of a one-time setting for
this session, and a persistent setting.  Code that calls customize
functions should similarly respect the user, no?

 > Otherwise all the callers end up doing this very awkward thing:

Why would they do that?  Maybe the smtpmail-smtp-* functions are
special in this regard, you can be the judge of that, but I would
think that most callers are simply trying to provide an even
higher-level front-end to Customize, and would respect its conventions
about user intent to make a change persistent.