bug#18094: 24.4.50; emacs_backtrace.txt

[Drew Adams <drew.adams@oracle.com>]

> This makes no sense to me.  The crash is here:
>   base_face = FACE_FROM_ID (f, base_face_id);
>   eassert (base_face);  <<<<<<<<<<<<<<<<<<<<<<<<<<
> 
> The argument base_face_id comes from the current mode line face, which
> must be a valid face. What in the world are you doing with your mode
> line format??

I use these faces on parts of the mode line:

(defface modelinepos-column-warning '((t (:foreground "Red")))
  "*Face used to highlight the modeline column number.
This is used when the current column number is greater than
`modelinepos-column-limit'."
  :group 'Modeline :group 'Convenience :group 'Help :group 'faces)

(defface modelinepos-region '((t :inherit region))
  "*Face used to highlight the modeline position and size when
the region is active."
  :group 'Modeline :group 'Convenience :group 'Help :group 'faces)

(defface modelinepos-region-acting-on '((t (:inherit region
  :box (:line-width 3 :color "Red"))))
  "*Face for modeline position & size when a command acts on active region."
  :group 'Modeline :group 'Convenience :group 'Help :group 'faces)

As for what in the world I am doing with my mode line format, the code
is here: http://www.emacswiki.org/emacs-en/download/modeline-posn.el.

At least that is much of what in the world I am doing with my mode line
format.  And this is what I use for face `mode-line-buffer-id':
((t (:overline "red" :underline "red"))).

And another piece of what in the world I am doing with my mode line
format is here:
http://www.emacswiki.org/emacs-en/download/bindings%2b.el.

And another piece, for Dired buffers, is function
`diredp-nb-marked-in-mode-name', from here:
http://www.emacswiki.org/emacs-en/download/dired%2b.el

And I sometimes dynamically put different things in the mode-line,
using this face:

(defface icicle-mode-line-help
    '((((background dark)) (:foreground "#AC4AAC4A0000"))
      (t (:foreground "Blue")))
  "*Face used to highlight help shown in the mode-line."
  :group 'Icicles-Completions-Display :group 'Icicles-Miscellaneous
  :group 'faces)

See functions `icicle-display-candidates-in-Completions'
`icicle-show-help-in-mode-line', and `icicle-show-in-mode-line' in
this file, for the code that does that:
http://www.emacswiki.org/emacs-en/download/icicles-fn.el.  It is
done at various times, including on `post-command-hook'.

I also have code that dynamically changes one or more lighters.
For example, `icicle-(un)highlight-lighter', in icicles-fn.el.

I also make changes to the mode line in certain modes.

For example, in Info, I (optionally) insert breadcrumbs in the mode
line.  The relevant code is in `Info-insert-breadcrumbs-in-mode-line',
`Info-set-mode-line' and `Info-breadcrumbs-in-mode-line-mode', here:
http://www.emacswiki.org/emacs-en/download/info%2b.el

And in Isearch, I update the lighter to show case-sensitivity.  The
code is `isearchp-highlight-lighter', here:
http://www.emacswiki.org/emacs-en/download/isearch%2b.el

That's a start wrt what in the world I am doing with my mode line
format.  There are other places where I change things in the
mode-line, but they are likely to be even less relevant.

FWIW, I am not doing anything new with my mode-line.  Whatever in
the world I am doing with my mode-line I have been doing for years now.