From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <e@80x24.org>
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net
X-Spam-Level: 
X-Spam-ASN:  
X-Spam-Status: No, score=-4.0 required=3.0 tests=ALL_TRUSTED,BAYES_00
	shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2
Received: from localhost (dcvr.yhbt.net [127.0.0.1])
	by dcvr.yhbt.net (Postfix) with ESMTP id A197F1F4B5;
	Sun, 17 Nov 2019 01:24:04 +0000 (UTC)
Date: Sun, 17 Nov 2019 01:24:04 +0000
From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: Re: Filter example for ML footers
Message-ID: <20191117012404.GA427@dcvr>
References: <20191116175251.ykhpp6zuo5f6kqiy@chatter.i7.local>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20191116175251.ykhpp6zuo5f6kqiy@chatter.i7.local>
List-Id: <meta.public-inbox.org>

Konstantin Ryabitsev <konstantin@linuxfoundation.org> wrote:
> Hello:
> 
> Groups.io adds a super-obnoxious footer to all outgoing messages, and I 
> would like to be able to filter that out. Example:
> 
> https://lore.kernel.org/keys/20191111161300.hc7vb7rcb45gsqmg@chatter.i7.local/
> 
> The obnoxious footer can be either part of the main body (default
> "chaotic evil" version) or a separate mime-part (configurable, "lawful 
> evil").
> 
> I tried to wrap my brain around existing filters, but they don't quite 
> do the exact thing I need, specifically:
> 
> - if there is a text/plain mime-part with just "^-=-=.*=-=-$", remove it
> - if there is no more content left after removing the footer, nuke the 
>   entire mime-part
> 
> Any quick pointers how this can be accomplished? 

Maybe check the call to ->walk_parts and ->body_str_set in
lib/PublicInbox/Filter/RubyLang.pm.

Also, historical versions of lib/PublicInbox/Filter.pm
did a lot more with MIME parts replacment and removal:
https://public-inbox.org/meta/8b78a44163743dcd4a235a1bc661471e29f091e6/s/
(but was too intrusive with DKIM)