From 5465a3d9a694104da0d07b637cc8bec30bfe6377 Mon Sep 17 00:00:00 2001
From: Chris Leonard <35844395+crleonard@users.noreply.github.com>
Date: Tue, 28 Apr 2026 18:17:37 +0100
Subject: [PATCH 1/2] Allow license headers without CONTRIBUTORS.txt

---
 .github/workflows/scripts/check-license-header.sh | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/scripts/check-license-header.sh b/.github/workflows/scripts/check-license-header.sh
index 2677b084..0d9f7466 100755
--- a/.github/workflows/scripts/check-license-header.sh
+++ b/.github/workflows/scripts/check-license-header.sh
@@ -122,10 +122,20 @@ while IFS= read -r file_path; do
     | sed -E -e 's/20[12][0123456789] ?[-–] ?20[12][0123456789]/YEARS/' -e 's/20[12][0123456789]/YEARS/' \
   )
 
-  if ! diff -u \
+  if ! diff_output=$(diff -u \
     --label "Expected header" <(echo "${expected_file_header}") \
-    --label "${file_path}" <(echo "${normalized_file_header}")
+    --label "${file_path}" <(echo "${normalized_file_header}"))
   then
+    expected_file_header_without_contributors=$(echo "${expected_file_header}" | sed '/CONTRIBUTORS\.txt/d')
+    normalized_file_header_without_contributors=$(echo "${normalized_file_header}" | sed '/CONTRIBUTORS\.txt/d')
+    if [ "${expected_file_header}" != "${expected_file_header_without_contributors}" ] \
+      && diff -u \
+        --label "Expected header" <(echo "${expected_file_header_without_contributors}") \
+        --label "${file_path}" <(echo "${normalized_file_header_without_contributors}") > /dev/null
+    then
+      continue
+    fi
+    echo "${diff_output}"
     paths_with_missing_license+=("${file_path} ")
   fi
 done <<< "$file_paths"

From 87d95e9d01e5262ff996c934d6f0d7e25c954d00 Mon Sep 17 00:00:00 2001
From: Chris Leonard <35844395+crleonard@users.noreply.github.com>
Date: Tue, 28 Apr 2026 18:17:40 +0100
Subject: [PATCH 2/2] Create check-license-header.sh

---
 tests/check-license-header.sh | 58 +++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100755 tests/check-license-header.sh

diff --git a/tests/check-license-header.sh b/tests/check-license-header.sh
new file mode 100755
index 00000000..3f08e363
--- /dev/null
+++ b/tests/check-license-header.sh
@@ -0,0 +1,58 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the Swift.org open source project
+##
+## Copyright (c) 2026 Apple Inc. and the Swift project authors
+## Licensed under Apache License v2.0 with Runtime Library Exception
+##
+## See https://swift.org/LICENSE.txt for license information
+##
+##===----------------------------------------------------------------------===##
+
+set -euo pipefail
+
+repo_root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+tmpdir=$(mktemp -d)
+trap 'rm -rf "${tmpdir}"' EXIT
+
+mkdir -p "${tmpdir}/.github/workflows/scripts"
+cp "${repo_root}/.github/workflows/scripts/check-license-header.sh" "${tmpdir}/.github/workflows/scripts/check-license-header.sh"
+
+cd "${tmpdir}"
+git init -q
+
+cat > WithContributors.swift <<'EOF'
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Logging API open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift Logging API project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Logging API project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+EOF
+
+cat > WithoutContributors.swift <<'EOF'
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Logging API open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift Logging API project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+EOF
+
+git add WithContributors.swift WithoutContributors.swift
+
+PROJECT_NAME="Swift Logging API" .github/workflows/scripts/check-license-header.sh