A customize idea...

[David Kastrup]

Hi,

I was just thinking of the following: in AUCTeX, there is a large
customizable list TeX-command-list.  When people customize it,
obviously after updating AUCTeX the next time, any changes of the
default value get lost.

It would be probably nice if customizing such a variable would also
record the sxhash value of its _default_ value.  If at a later time it
is found that the hash of the default value has changed, the user gets
notified and can choose whether he wants to keep his customized value
(in which case the sxhash gets updated to that of the new default),
delete his customization, or get diff-buffers started on two
customization buffers run on both the customized and new default value
(a three-way diff is not possible unless the complete old default gets
recorded instead of just the sxhash, but that sounds like overkill).

Another possibility would be to have a library for this which acts
only on demand.  The library would then have a command to record the
complete defaults for everything that has been customized, writing
them out to a separate file.  After updating Emacs, one would then be
able to call a "Custom-consolidate" which would then be able to do the
three-way merge on old defaults, new defaults and customized settings.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum