Re: How to modify a function of a package

[Philip Kaludercic <philipk@posteo.net>]

Maske <maske1foro@gmail.com> writes:

> Hi
>
> I have installed a package and I want to modify a function of it, but
> not in the package itself, because if there is an update it would stop
> working, so I have added the function modified in my init file. But,
> it doesn't work. The package behavior is not altered.

If you know that it will only affect you and you can reasonably assume
that the feature will be stable in future versions, you can take a look
at `(elisp) Advising Functions'.  Specifically the function
`define-advice' could be of use, here is an example that pulses the
region evaluated using C-M-x:

(define-advice eval-region (:after (start end &rest _))
  (pulse-momentary-highlight-region start end))

The other option is always to share your contribution with the author
and all other users.  This might require some discussions and
generalising whatever you changed, and even if nothing is accepted you
probably stand learning something new, so it is always worth the try.
You can use package-vc-install to fetch the package sources (which btw.
doesn't loose local modifications on updating, but therefore might
require resolving a merge-conflict), and package-vc-submit-patch to send
the change to the maintainer.

> What would be the correct way?
>
> Best regards