test

    return "webp";

}

// CSS url() scanning (see this function's two CustomCss/globalCss call

// sites below) can't distinguish a background-image from an @font-face src

// -- both use identical url(...) syntax -- so without this every webfont a

// page's CSS references gets treated as an image to re-host, then fails the

// media-import fetch's "image/" Content-Type check and shows up to the user

// as an inexplicable "N Bild(er) fehlgeschlagen" for files that were never

// images (confirmed against a real page: 21 of 55 collected "image" urls

// were manrope .woff/.woff2/.ttf webfonts from its @font-face rules, the

// exact 21 that always failed). Filtered by extension since that's known

// before ever making the request; genuine images with no extension at all

// (common on CDNs, see guessImageExtFromBytes) still pass through untouched

// -- this only excludes the handful of extensions that are unambiguously

// never an image.

static bool isExternalImageUrl(const std::string &s) {

    return s.compare(0, 7, "http://") == 0 || s.compare(0, 8, "https://") == 0;

    if (s.compare(0, 7, "http://") != 0 && s.compare(0, 8, "https://") != 0) return false;

    static const std::vector<std::string> nonImageExts = {

        ".woff2", ".woff", ".ttf", ".otf", ".eot"

    };

    std::string path = s;

    size_t q = path.find_first_of("?#");

    if (q != std::string::npos) path.resize(q);

    for (const auto &ext : nonImageExts) {

        if (path.size() >= ext.size() &&

            std::equal(ext.begin(), ext.end(), path.end() - ext.size(),

                       [](char a, char b) { return std::tolower(static_cast<unsigned char>(a)) == b; }))

            return false;

    }

    return true;

}

// Recursively collects every distinct absolute http(s) `src` from the