[Haskell-cafe] GPL License of H-Matrix and prelude numeric

[John Millikin]

On Tue, Jan 25, 2011 at 21:51, Chris Smith <cdsmith at gmail.com> wrote:
> On Tue, 2011-01-25 at 21:41 -0800, John Millikin wrote:
>> Licensing is a property of the code, not the package; Cabal's
>> licensing field is only a useful shorthand for "most of the code here
>> is covered by...".
>
> That would be a very dangerous position to take.  When the Cabal license
> field informs someone that something is licensed under the BSD, I think
> any reasonable person would assume that means ALL of the code is
> licensed under the BSD, and without added restrictions.  We're being
> extremely unhelpful if developers have to read through every source file
> in every library they use, and all of its indirect dependencies, to make
> sure there's not an additional restriction in there somewhere.

I don't think a reasonable person would assume that. Based on the
almost universal habit of noting the license in source file comment
headers, a reasonable programmer would know to check the status of any
code he wants to copy into his own works.

For example, if I copy some BSD3 code into one of my GPL'd libraries,
that code remains BSD3 (and owned by the original author). The Cabal
field will still say GPL, because most of the code is GPL, but some of
it is not.

Alternatively, I could bundle a GPL'd test script with BSD3 code. The
code itself (and hence Cabal file) is BSD3, but not everything in the
archive is.

The package's dependencies are irrelevant, unless the package's code
was itself copied from one of its deps.