Re: is copyleft packaging bad for Debian?

Jeremy Stanley <[email protected]> Tue, 3 Feb 2026 23:08:09 +0000
Newsgroups	gmane.linux.debian.devel.project
Message-ID	<[email protected]>
On 2026-02-03 11:11:57 -0800 (-0800), Russ Allbery wrote:
[...]
> What nearly every free software project does in practice is make an 
> assumption. That assumption goes roughly like this:
>
>    You voluntarily submitted your work to my project and asked for it to
>    be included, so I am going to assume that this means you agree to the
>    standard conventions of free software and are okay with your work
>    being included under the free software license that the work is
>    already covered by. Asking you to confirm this explicitly is annoying
>    and requires another back-and-forth, so I'm just going to assume we're
>    all adults here and you wouldn't have sent me the patch if you didn't
>    want me to use it.
>
> This is not legally rigorous, but it's also not *entirely* void of legal 
> meaning either. There are a bunch of legal concepts sort of vaguely 
> floating around in this area that have names like "promissary estoppel" 
> that I am not even remotely qualified to analyze, but which roughly amount 
> to a general informal principle that people are entitled to assume that 
> you are a reasonable person and you mean what you are clearly implying. If 
> you try to sue someone for incorporating a patch that you sent them for 
> incorporation, it's not an unreasonable assumption that a judge is going 
> to ask questions like "if you didn't want them to use your patch, why did 
> you send it to them" and "if you didn't want your work covered under the 
> same license as the software you submitted it to, why didn't you say so" 
> and arrive at reasonable conclusions.
[...]

Also not a lawyer, but wanted to point out that the strength of this 
assumption does vary somewhat from license to license too. In 
particular, copyleft licenses sort of try to encode it insofar as if 
you're violating the patch author's implicit copyright by including 
their derivative work into the project, then they were likely also 
violating the project's copyright license by distributing that 
modification to you under infringing terms.

The popularity of the legal workarounds you enumerated also vary 
somewhat by license, owing in great part to the fact that not all 
free/libre open source software licenses these days are purely 
copyright licenses: some also require patent grants, and for even 
longer we've had some that mandated or restricted certain uses of 
associated trademarks as well (thankfully not en vogue in recent 
years). So, depending on what additional sorts of intellectual 
property a license might cover, the project's legal counsel may push 
for stronger binding contracts to make sure the intent is clear... 
especially since IP like patents and trademarks tend to be 
jurisdiction-dependent and aren't covered by broad international 
convention the way copyright has been.
-- 
Jeremy Stanley
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