Re: Building emacs with and without X -- packaging question.

[Rob Browning <rlb@defaultvalue.org>]

Richard Stallman <rms@gnu.org> writes:

>     Sure I can try.  I presume you're talking about this diff:
>
>     -(put 'frames 'custom-loads '( "desktop" "ediff-wind" "faces" "frame" "imenu" "menu-bar" "rsz-mini" "scroll-bar" "two-column"))
>     +(put 'frames 'custom-loads '( "desktop" "ediff-wind" "faces" "frame" "imenu" "menu-bar" "rsz-mini" "two-column"))
>
> That one and the other one, both.
>
>     Is this one related, or likely something else?
>
>     -(custom-put-if-not 'gnus-article-x-face-command 'custom-version "21.1")
>     -(custom-put-if-not 'gnus-article-x-face-command 'standard-value t)
>
> There is no way of knowing a priori whether they are related.

I finally had time to work on this, and I think I've tracked it down.
In cus-dep.el we have:

		    (let ((expr (read (current-buffer))))
		      (condition-case nil
			  (progn
			    (eval expr)
			    (put (nth 1 expr) 'custom-autoloaded is-autoloaded)
			    (put (nth 1 expr) 'custom-where name))
			(error nil))))

Note that the condition-case ignores errors.  However, if you rewrite
the above to actually catch the signalled-condition data and print it
via message, you will find that when compiling --with-x=no, there's an
error while handling both the scroll-bar-mode and
gnus-article-x-face-command defcustoms.  In the scroll-bar-mode case
this appears to be because set-scroll-bar-mode-1 is undefined, even
though it's used as the :set value in the relevant defcustom:

  (defcustom scroll-bar-mode
    (if (eq system-type 'windows-nt) 'right 'left)
    "*Specify whether to have vertical scroll bars, and on which side.
  Possible values are nil (no scroll bars), `left' (scroll bars on left)
  and `right' (scroll bars on right).
  To set this variable in a Lisp program, use `set-scroll-bar-mode'
  to make it take real effect.
  Setting the variable with a customization buffer also takes effect."
    :type '(choice (const :tag "none (nil)")
                   (const left)
                   (const right))
    :group 'frames
    :set 'set-scroll-bar-mode-1)

The actual condition-case signalled-condition data for this error is
(void-function set-scroll-bar-mode-1), and removing the :set line from
the defcustom fixes the problem, at least to the extent that the
scroll-bar related diff in cus-dep.el goes away.  For
gnus-article-x-face-command, the condition-case signalled-condition
data is (void-variable gnus-article-compface-xbm).

If my analysis is right, is this something that should be fixed, and
if so, what would be the right way to fix it?

Thanks

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
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