From 19f9fecb33c164b1f500dca2023e0c8a4a10ce1c Mon Sep 17 00:00:00 2001
From: Bo Anderson <mail@boanderson.me>
Date: Fri, 17 Jul 2020 14:14:12 +0100
Subject: [PATCH 1/2] dev-cmd/update-license-data: fail if not changed rather
 than on change

---
 Library/Homebrew/dev-cmd/update-license-data.rb | 6 +++---
 docs/Manpage.md                                 | 4 ++--
 manpages/brew.1                                 | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/update-license-data.rb b/Library/Homebrew/dev-cmd/update-license-data.rb
index 952a46ee27..456a7b38ec 100644
--- a/Library/Homebrew/dev-cmd/update-license-data.rb
+++ b/Library/Homebrew/dev-cmd/update-license-data.rb
@@ -16,8 +16,8 @@ module Homebrew
 
          Update SPDX license data in the Homebrew repository.
       EOS
-      switch "--fail-if-changed",
-             description: "Return a failing status code if current license data's version is different from " \
+      switch "--fail-if-not-changed",
+             description: "Return a failing status code if current license data's version is the same as " \
                           "the upstream. This can be used to notify CI when the SPDX license data is out of date."
       switch "--commit",
              description: "Commit changes to the SPDX license data."
@@ -33,7 +33,7 @@ module Homebrew
     data_url = "https://raw.githubusercontent.com/spdx/license-list-data/#{latest_tag}/json/licenses.json"
     curl_download(data_url, to: SPDX_PATH, partial: false)
 
-    Homebrew.failed = !system("git", "diff", "--stat", "--exit-code", SPDX_PATH) if args.fail_if_changed?
+    Homebrew.failed = system("git", "diff", "--stat", "--exit-code", SPDX_PATH) if args.fail_if_not_changed?
 
     return unless args.commit?
 
diff --git a/docs/Manpage.md b/docs/Manpage.md
index a41eb26a2f..192e877410 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -1052,8 +1052,8 @@ directory.
 
  Update SPDX license data in the Homebrew repository.
 
-* `--fail-if-changed`:
-  Return a failing status code if current license data's version is different from the upstream. This can be used to notify CI when the SPDX license data is out of date.
+* `--fail-if-not-changed`:
+  Return a failing status code if current license data's version is the same as the upstream. This can be used to notify CI when the SPDX license data is out of date.
 * `--commit`:
   Commit changes to the SPDX license data.
 
diff --git a/manpages/brew.1 b/manpages/brew.1
index 25e5ce2cc4..d0e45e813a 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -1361,8 +1361,8 @@ Initialise a Git repository in the unpacked source\. This is useful for creating
 Update SPDX license data in the Homebrew repository\.
 .
 .TP
-\fB\-\-fail\-if\-changed\fR
-Return a failing status code if current license data\'s version is different from the upstream\. This can be used to notify CI when the SPDX license data is out of date\.
+\fB\-\-fail\-if\-not\-changed\fR
+Return a failing status code if current license data\'s version is the same as the upstream\. This can be used to notify CI when the SPDX license data is out of date\.
 .
 .TP
 \fB\-\-commit\fR

From 4a167d79434f7d4498f6243f3cfbb0faa2b9daba Mon Sep 17 00:00:00 2001
From: Bo Anderson <mail@boanderson.me>
Date: Fri, 17 Jul 2020 02:34:23 +0100
Subject: [PATCH 2/2] workflows: auto create PRs for license data updates

---
 .github/workflows/spdx.yml  | 41 +++++++++++++++++++++++++++++++++++++
 .github/workflows/tests.yml |  5 -----
 2 files changed, 41 insertions(+), 5 deletions(-)
 create mode 100644 .github/workflows/spdx.yml

diff --git a/.github/workflows/spdx.yml b/.github/workflows/spdx.yml
new file mode 100644
index 0000000000..c371eb64af
--- /dev/null
+++ b/.github/workflows/spdx.yml
@@ -0,0 +1,41 @@
+name: Update license data
+
+on:
+  schedule:
+    - cron: '* */12 * * *'
+
+jobs:
+  spdx:
+    runs-on: ubuntu-latest
+    env:
+      HOMEBREW_NO_ANALYTICS: 1
+      HOMEBREW_NO_AUTO_UPDATE: 1
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Configure Git
+        uses: Homebrew/actions/git-user-config@master
+        with:
+          username: BrewTestBot
+
+      - name: Setup Homebrew
+        run: |
+          HOMEBREW_REPOSITORY="$(brew --repo)"
+          rm -rf "$HOMEBREW_REPOSITORY"
+          ln -s "$GITHUB_WORKSPACE" "$HOMEBREW_REPOSITORY"
+
+      - name: Update license data
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          cd "$GITHUB_WORKSPACE/Library/Homebrew"
+          if brew update-license-data --commit --fail-if-not-changed; then
+            SPDX_VERSION=$(jq -er .licenseListVersion data/spdx.json)
+            if ! git ls-remote --exit-code --heads origin "spdx-$SPDX_VERSION"; then
+              git checkout -b "spdx-$SPDX_VERSION"
+              git push origin "spdx-$SPDX_VERSION"
+              hub pull-request -m "$(git log -1 --format='%s')"
+            fi
+          fi
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index b335d0330f..2ee3d3d130 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -114,11 +114,6 @@ jobs:
     - name: Run brew man
       run: brew man --fail-if-changed
 
-    - name: Check for outdated license data
-      run: brew update-license-data --fail-if-changed
-      env:
-        HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
     - name: Run brew tests
       run: |
         # brew tests doesn't like world writable directories