workflows/lint: add clang-format on changed files

The entire codebase is not ready to be clang-formatted and probably
never will be, but we can at least check if the changes in new pull
requests follow our coding style.

.clang-format

@@ -0,0 +1,20 @@
+BasedOnStyle: Google
+BreakBeforeBraces: Linux
+IndentWidth: 4
+PPIndentWidth: 1
+IndentPPDirectives: AfterHash
+IndentCaseLabels: false
+IncludeBlocks: Preserve
+SortIncludes: true
+SpaceAfterCStyleCast: false
+AllowShortIfStatementsOnASingleLine : Never
+AllowShortLoopsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: false
+AlignArrayOfStructures: Right
+AlignConsecutiveAssignments: true
+AllowAllParametersOfDeclarationOnNextLine: false
+Cpp11BracedListStyle: true
+InsertNewlineAtEOF: true
+SpacesInContainerLiterals: false
+BinPackArguments: true
+BinPackParameters: true

.github/workflows/lint.yml

@@ -39,3 +39,19 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: chartboost/ruff-action@v1
+
+  clang-format-lint:
+    runs-on: ubuntu-24.04
+    container:
+      image: "registry.opensuse.org/home/mia/images/images/mpv-ci:stable-deps"
+    if: github.event_name == 'pull_request'
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 50
+      - name: Configure git
+        # Workaround to avoid "fatal: detected dubious ownership in repository" error.
+        run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
+      - name: Check Formatting
+        run: |
+          git clang-format ${{ github.event.pull_request.base.sha }} --diff