spdy: fix duplicate license headers, add LICENSE, PATENTS, and update NOTICE

[thaJeztah]

• alternative to, closes Fix Issue 104: supply original BSD-style license #105
• fixes LICENSE file missing bsd-style license referenced from spdy/dictionary.go #104

update ltag module name

The repository was moved to the containerd org; also fix some minor
issues in the script to make it valid for POSIX shell.

spdy: fix duplicate license headers

The Apache 2 headers were added in 0c4d6b8,
which overlooked that these files were forked from the Go project, and
BSD licensed.

• Remove the Apache 2 headers
• Update the validate script to ignore the spdy directory

update NOTICE, add LICENSE and PATENTS in spdy directory

Code in the spdy directory was derived from the Go project (golang.org/x/net)
in commmit 866205e, because the code was removed
in upstream in golang/net@ff8eb9a

This patch:

• Adds the correct license and patents files to the directory.
• Adds a mention to the NOTICE file at the root of the repository.

[Copilot]

Pull request overview

Updates licensing/attribution for the spdy/ code (derived from the Go project) and adjusts header-validation tooling/CI to accommodate that directory.

Changes:

• Remove the Apache-2.0 Docker header blocks from spdy/*.go and rely on Go’s BSD-style headers; add “Modifications Copyright … Docker Inc.” where applicable.
• Add Go’s BSD 3-Clause LICENSE and Go PATENTS grant into spdy/, and document this in the project NOTICE.
• Switch header validation tooling from kunalkushwaha/ltag to containerd/ltag, and exclude spdy/ from header validation.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
spdy/write.go	Removes Docker Apache header block; retains Go BSD-style header.
spdy/read.go	Removes Docker Apache header block; retains Go BSD-style header.
spdy/dictionary.go	Removes Docker Apache header block; retains Go BSD-style header.
spdy/types.go	Adds Docker modifications attribution line alongside Go BSD-style header.
spdy/spdy_test.go	Adds Docker modifications attribution line alongside Go BSD-style header.
spdy/LICENSE	Adds BSD 3-Clause license text for the derived Go code.
spdy/PATENTS	Adds Go patent grant text for the derived Go code.
scripts/validate/fileheader	Uses containerd/ltag and excludes spdy/ from header validation.
.github/workflows/ci.yaml	Installs containerd/ltag in CI for header validation.
NOTICE	Documents the derived spdy/ code and where its license/patent grant live.

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[thaJeztah]

Thx! @bbadour let me know if this works for you, then this is probably OK to merge.

[bbadour]

looks good to me

[thaJeztah]

Thanks! Let me bring this one in, and thanks for raising the issue; definitely looks like it was overlooked at the time when #53 was merged (looks like the removal caused builds to be broken, so probably checking licenses was not at the top of the list at that time) 😅