[gentoo-dev] Re: Emacs settings for ebuild scripts

[Andreas Voegele <voegelas@users.sourceforge.net>]

Mikael Hallendal writes:

> In Emacs21 I get an error when hitting TAB telling me I'm not in
> shell-script-mode. You know what's causing that?

I don't know if this is a feature or a bug in Emacs 21.  The function
sh-must-be-shell-mode in sh-script.el looks like this:

(defun sh-must-be-shell-mode ()
  "Signal an error if not in Shell-script mode."
  (unless (eq major-mode 'sh-mode)
    (error "This buffer is not in Shell-script mode")))

IMHO the expression (eq major-mode 'sh-mode) should be replaced with
(derived-mode-p 'sh-mode).

I'll ask the Emacs developers.

In the meanwhile the following code, which includes an advice for
sh-must-be-shell-mode, can be used:

(define-derived-mode ebuild-script-mode
  sh-mode "Ebuild-script" nil
  (setq tab-width 4))

(setq auto-mode-alist
      (append
       '(("\\.ebuild$" . ebuild-script-mode))
       auto-mode-alist))

(defadvice sh-must-be-shell-mode
  (around sh-must-be-shell-mode-around activate)
  "Accept modes derived from sh-mode."
  (unless (derived-mode-p 'sh-mode)
    ad-do-it))

-- 
Andreas