Re: "CHANGED outside Customize" in frames customization group

[Richard Stallman]

    IIUC `custom-reevaluate-setting' can be used to set a variable after
    some environment value has been established as for `blink-cursor-mode'.
    The situation seems completely different for `default-frame-alist'.

In what way is it different?

      The first reason is immediately visible
    when starting Emacs without your .emacs.  The value is here:

    ((left-fringe) (right-fringe) (menu-bar-lines . 1) (tool-bar-lines . 1))

    I know how to get rid of the -fringe entries.

ISTR someone recently posted a patch that would affect the handling
of fringes in `default-frame-alist'.  Would they get rid of those?

                                                   But I don't know what to
    do with the -line entries (which are BTW already there in Emacs 21).

Why does anything need to be done with them?
Could you just leave them alone?
Or else change the numbers?

    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.

    A second reason is the function `modify-all-frames-parameters'.  This
    function may set `default-frame-alist'.  Customize `tool-bar-mode' or
    `fringe-mode' and you will change your `default-frame-alist' settings.

I don't see a problem in that.  Why do you think it is a problem?
What aspect of it is the problem?

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.