Re: "CHANGED outside Customize" in frames customization group

[Richard Stallman <rms@gnu.org>]

    `frame-notice-user-settings' may set the value of `default-frame-alist'
    overriding a saved or standard value.  The value of `blink-cursor-mode'
    is not reset by Emacs.

Ok, but why does that matter for this issue?

     >     Delete them in the customization buffer, save your settings, restart
     >     Emacs, and here they are again.
     >
     > That is arguably a bug, and maybe we should fix it.
     > However, I do not see that this bug is so grave
     > that we should conclude that `default-frame-alist' is
     > unsuitable for use with Custom.

    The bug causes the "CHANGED outside Customize ..." state.

Here's an idea.  We can create a new variable
`command-args-frame-alist', and make the functions which obey
`default-frame-alist' use `command-args-frame-alist' too.

Settings such as `menu-bar-lines', which are set by arguments and X
resources can go in `command-args-frame-alist', and would not affect
`default-frame-alist'.  One consequence would be that the values
specified by command line options and X resources would override your
customizations.  That seems correct.

    Customizing `fringe-mode' calls `modify-all-frames-parameters' which
    sets `default-frame-alist'.  I'm now told that `default-frame-alist' was
    CHANGED outside Customize although all I actually did was _customizing_
    some option.

The solution to that is just to inform Custom about the change, so it
will realize that the change to `default-frame-alist' was made within
Custom.

It's just a bug, it just needs to be fixed.

     > If the problem is in some detail of the behavior of Custom when it is
     > used on `default-frame-alist', maybe we can fix that detail.
     > For instance, maybe those other commands should do somethingto inform
     > Custom of the changes, so that it looks like `default-frame-alist'
     > was set using Custom.

    Suppose I set and save a new value for `fringe-mode'.  Should Emacs
    automatically set and save the new value for `default-frame-alist'?

Maybe it should, but that would require a new Custom feature:
dependencies, "If you save `foo', always save `bar' too".