Update license expressions to new syntax

[waldyrious]

Updating formulae license expressions in the context of #58225, now that richer license syntax has been made available in #7953 and #8260.

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• Is your test running fine brew test <formula>, where <formula> is the name of the formula you're submitting?
• Does your build pass brew audit --strict <formula> (after doing brew install <formula>)?

---

[waldyrious]

Note: audit fails for two formulae:

$ brew audit $(git show --name-only | sed '1,2d')
mongoose:
  * Formula mongoose contains non-standard SPDX licenses: ["Cesanta"].
    For a list of valid licenses check: https://spdx.org/licenses/
ttf2eot:
  * Formula ttf2eot contains non-standard SPDX licenses: ["BSD-*"].
    For a list of valid licenses check: https://spdx.org/licenses/
Error: 2 problems in 2 formulae detected

What should I do with these?

• Mongoose is be dual-licensed under GNU GPL-2.0 and custom licensing for commercial use. See a79bfeb in #58678 (cc @chenrui333). How is this arrangement typically represented in these license expressions?

• ttf2eot's license is, according to the README:

  Derived from WebKit, so BSD/LGPL 2/LGPL 2.1.

  The specific BSD is not identified, neither in ttf2eot, nor in WebKit itself. I suppose one might dig it from WebKit's source files, but I'm not confident I'd be able to determine it with sufficient certainty. I'd suggest keeping the license expression pointing to LGPL-2.1 alone as it's the only thing we can be certain of at this point, and maybe leaving the comment with the explanation. See also cdba946 from #59030.

[Rylan12]

Thanks for the PR, @waldyrious!

A few comments:

[Rylan12]

Not sure how to handle this exactly. According to the license file:

This project is transitioning from an MIT-only license to a dual MIT/Apache-2.0 license.
Unless otherwise noted, all code contributed prior to 2019-05-06 and not contributed by
a user listed in this signoff issue is
licensed under MIT-only. All new contributions (and past contributions since 2019-05-06)
are licensed under a dual MIT/Apache-2.0 license.

I don't think we can use :any_of because that implies that the MIT doesn't have to apply. In reality, it seems to be MIT and the option of Apache-2.0 as well. It feels like maybe it should be:

  license all_of: [
    "MIT",
    any_of: ["MIT", "Apache-2.0"],
  ]

Probably good to get another maintainer opinion on this.

[waldyrious]

Sounds reasonable to me. I'll make the change you're proposing, but will be happy to update to follow whatever consensus emerges.

[Rylan12]

Suggested change

	license any_of: ["LGPL-2.0", "BSD-*"]
	license any_of: ["LGPL-2.0-only", "BSD-2-Clause"]

Based on: https://webkit.org/licensing-webkit/. Didn't see any indication of -only or -or-later so went with -only. Maybe another maintainer can find some more info?

If we're not sure about that, we should probably:

Suggested change

	license any_of: ["LGPL-2.0", "BSD-*"]
	license :cannot_represent

[waldyrious]

I do see at the end of that page this note:

WebKit open source web browser engine.
Copyright (C) 2015 Apple, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

Doesn't that make it clear the -or-later versioning is intended?

[Rylan12]

No, that's part of the standard -or-later and -only license.

See the SPDX entries for LGPL-2.0-only and LGPL-2.0-or-later. They both contain the above lines in the "How to Apply These Terms to Your New Libraries" section.

We really need to see the source files to see which header is used. That will be able to tell us whether -only or -or-later is more approriate.

[waldyrious]

Ah, I see. Well, that's confusing 🙃 I'll look into WebKit's source files, then.

[waldyrious]

Ok, I cloned the repo (from this mirror) and ran a search in the source files. It seems pretty clear that the -or-later variant is the intended one:

$ rg -l 'the Free Software Foundation; either' | wc -l
2982

$ rg -l 'the Free Software Foundation; version' | wc -l
0

See also this commit for an example of the typical license headers they use.

[waldyrious]

(That said, it seems that in this case we'd need to use all_of rather than any_of, since each file is only licensed under one of the two licenses; WDYT?)

[waldyrious]

Thanks for the thorough review @Rylan12! I'll make the obvious changes right away, and will leave the unclear ones to when others have a chance to chime in.

[Rylan12]

Sorry, maybe I wasn't clear enough here. No quotes or brackets needed:

Suggested change

	license any_of: ["GPL-2.0-only"]
	license "GPL-2.0-only"

[waldyrious]

Oops! That was definitely an overlook on my side — it was late here 😅 I'll update.

[Rylan12]

Additionally, next time you update the PR, can you separate the changes to one-commit-per-formula with the message formula: update license expression to new syntax (or similar) for each?

Thanks, again!

[BrewTestBot]

🤖 A scheduled task has triggered a merge.

[Rylan12]

Thanks, @waldyrious!