Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Currently special-mode is under used, so patches to use it in more
> places are very welcome.

Here is a `bzr bundle' to make use of the `special-mode' in more places.
Modes that were under special treatment:

archive-mode 
bookmark-bmenu-mode 
doc-view-mode 
image-mode 
occur-mode
tar-mode

In `archive-mode' I needed to get rid of optional argument `force',
which was used to avoid somebody switching manually the mode, and since
the symbol's become interactive, there is a danger (accoring to the
comments - corruption). So I just added a help notice, saying that the
user should not call `archive-mode' on her own.

For the similar reasons I've left alone `dired-mode' and friends, as
this takes arguments. (which are used).

I didn't touch `ibuffer-mode' as this assert explicitly that the mode
should not be derived (not sure why!), due too:
`ibuffer-assert-ibuffer-mode' called from several places, and breaks
`ibuffer' badly.

These are not all the places were we should consider inheriting from
special mode, possibly many other places where we could replace `defun'
with `define-derived-mode'. Also I've noticed some incosistency across
key-bindings, or duplications.

Cheers;
Wojciech