name: Prepare baseline Git compatibility binary
description: Restore or build the pinned Linux Git binary for the compatibility contract.

runs:
  using: composite
  steps:
    # The default-branch warmer shares this key across PRs; a PR save is private to its merge ref.
    # Cache eviction remains possible, so keep the checksum-verified cold build below.
    - name: Cache baseline Git build
      uses: actions/cache@v5
      with:
        path: ~/.cache/orca-git-compat/git-2.25.5
        key: git-compat-baseline-${{ runner.os }}-${{ runner.arch }}-2.25.5-submodule

    # Finish the CPU-heavy build before any timed compatibility lanes start.
    - name: Build the baseline Git binary
      shell: bash
      run: |
        archive="$RUNNER_TEMP/git-2.25.5.tar.gz"
        source="$HOME/.cache/orca-git-compat/git-2.25.5"
        if [ -x "$source/git" ] && [ -x "$source/git-submodule" ] \
          && [ -f "$source/git-sh-setup" ] && [ -f "$source/git-sh-i18n" ] \
          && [ -f "$source/git-parse-remote" ] && [ -x "$source/git-sh-i18n--envsubst" ]; then
          exit 0
        fi
        curl -fsSL https://www.kernel.org/pub/software/scm/git/git-2.25.5.tar.gz -o "$archive"
        echo "41662c52fc16fec4963bfc41075e71f8ead6b5e386797eb6f9a1111ff95a8ddf  $archive" \
          | sha256sum --check
        mkdir -p "$source"
        tar -xzf "$archive" -C "$source" --strip-components=1
        make -C "$source" -j"$(nproc)" \
          NO_GETTEXT=YesPlease NO_TCLTK=YesPlease NO_PYTHON=YesPlease \
          git git-submodule git-sh-setup git-sh-i18n git-parse-remote git-sh-i18n--envsubst
        # Object files are no longer needed after linking the cached binary.
        find "$source" -name '*.o' -delete