Fixes #5170 - Set default values only if not already customized

[opie4624]

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[robbyoconnor]

@opie4624 thanks <3

[opie4624]

I think this could stand to see a bit more polish over time. There are lots of defaults that layers override that could stand to have a better "standardized" way to set them that would still honor user's settings via Customize.

Relevant discussion in chat: https://gitter.im/syl20bnr/spacemacs?at=56b391733bd55a660df5688c

[syl20bnr]

Sorry but what's the issue you want to fix ? Can you open an issue to describe the problem first ? A PR is not the right place to do this.

[reactormonk]

I suggest something along the lines of https://gist.github.com/reactormonk/f4322f4ac1a0dec68413b1ccf44e7c7a

[TheBB]

I think this, or something like it, is what we need to use.

custom-variable-p is unreliable because it doesn't seem to know whether a variable is customizable until its definition has been loaded, and it also returns true regardless of whether it actually has a custom value or not.

(defmacro spacemacs|setq (&rest args)
  (let (result)
    (while args
      (let ((variable (pop args))
            (form (pop args)))
        (push `(or (not (get ',variable 'customized-value))
                   (not (get ',variable 'saved-value))
                   (setq ,variable ,form))
              result)))
    `(progn ,@(reverse result))))

[opie4624]

When I was researching this for my org-mode issues, I found a comment buried on the customize page of emacswiki that stated customized-value is set if it has been customized and loaded from .emacs while saved-value is set if the value has been customized within the interactive customize interface during this session. So @TheBB's code is checking the right things.

Also customized-face is set for customized fonts. Again, saved-value is used when fonts are customized interactively in this session. In the code I submitted for the PR, I checked all 3 in the same place since it seemed a nice, clean way to check for customization anywhere in once place.

[TheBB]

Yes, I skipped the face stuff because you wouldn't use a setq macro for that. And I think going with a macro is the right choice here so that you wouldn't have to replicate the checking logic everywhere.

[syl20bnr]

Thank you for the PR, I pushed a commit which delays the application of custom settings, they are now applied after user-config.

See commit: e699f18