Re: undo-information kept for *occur*

[Chong Yidong]

martin rudalics <address@hidden> writes:

>> This is not correct, because it seems to leave buffer-undo-list
>> permanently set to t.  That prevents undoing of changes made by hand
>> by the user.
>>
>
> Locally binding `buffer-undo-list' around the `erase-buffer' in
> `occur-1' is trivial.  But `occur-mode' has this
>
>   (add-hook 'change-major-mode-hook 'font-lock-defontify nil t)
>
> which means I would have to bind `buffer-undo-list' whenever I change
> the major-mode for this buffer.  Locally bind `buffer-undo-list' around
> `kill-all-local-variables' in `occur-mode'?

I think for practical purposes the only signficant source of undo
information comes from the erase-buffer call.  The latter problem
seems to be negligible.  So I went ahead and bound buffer-undo-list
just for occur-1.

Thanks.