if ( $is_active && 'php' === $extension ) {

    $scrape_key   = md5( rand() );
    $transient    = 'scrape_key_' . $scrape_key;
    $scrape_nonce = strval( rand() );
    // It shouldn't take more than 60 seconds to make the two loopback requests.
    set_transient( $transient, $scrape_nonce, 60 );

    $cookies       = wp_unslash( $_COOKIE );
    $scrape_params = array(
        'wp_scrape_key'   => $scrape_key,
        'wp_scrape_nonce' => $scrape_nonce,
    );
    $headers       = array(
        'Cache-Control' => 'no-cache',
    );

    /** This filter is documented in wp-includes/class-wp-http-streams.php */
    $sslverify = apply_filters( 'https_local_ssl_verify', false );

    // Include Basic auth in loopback requests.
    if ( isset( $_SERVER['PHP_AUTH_USER'] ) && isset( $_SERVER['PHP_AUTH_PW'] ) ) {
        $headers['Authorization'] = 'Basic ' . base64_encode( wp_unslash( $_SERVER['PHP_AUTH_USER'] ) . ':' . wp_unslash( $_SERVER['PHP_AUTH_PW'] ) );
    }

    // Make sure PHP process doesn't die before loopback requests complete.
    set_time_limit( 300 );

    // Time to wait for loopback requests to finish.
    $timeout = 100;

    $needle_start = "###### wp_scraping_result_start:$scrape_key ######";
    $needle_end   = "###### wp_scraping_result_end:$scrape_key ######";

    // Attempt loopback request to editor to see if user just whitescreened themselves.
    if ( $plugin ) {
        $url = add_query_arg( compact( 'plugin', 'file' ), admin_url( 'plugin-editor.php' ) );
    } elseif ( isset( $stylesheet ) ) {
        $url = add_query_arg(
            array(
                'theme' => $stylesheet,
                'file'  => $file,
            ),
            admin_url( 'theme-editor.php' )
        );
    } else {
        $url = admin_url();
    }
    $url                    = add_query_arg( $scrape_params, $url );
    $r                      = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout', 'sslverify' ) );
    $body                   = wp_remote_retrieve_body( $r );
    $scrape_result_position = strpos( $body, $needle_start );

    $loopback_request_failure = array(
        'code'    => 'loopback_request_failed',
        'message' => __( 'Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.' ),
    );
    $json_parse_failure       = array(
        'code' => 'json_parse_error',
    );

    $result = null;
    if ( false === $scrape_result_position ) {
        $result = $loopback_request_failure;
    } else {
        $error_output = substr( $body, $scrape_result_position + strlen( $needle_start ) );
        $error_output = substr( $error_output, 0, strpos( $error_output, $needle_end ) );
        $result       = json_decode( trim( $error_output ), true );
        if ( empty( $result ) ) {
            $result = $json_parse_failure;
        }
    }

    // Try making request to homepage as well to see if visitors have been whitescreened.
    if ( true === $result ) {
        $url                    = home_url( '/' );
        $url                    = add_query_arg( $scrape_params, $url );
        $r                      = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout' ) );
        $body                   = wp_remote_retrieve_body( $r );
        $scrape_result_position = strpos( $body, $needle_start );

        if ( false === $scrape_result_position ) {
            $result = $loopback_request_failure;
        } else {
            $error_output = substr( $body, $scrape_result_position + strlen( $needle_start ) );
            $error_output = substr( $error_output, 0, strpos( $error_output, $needle_end ) );
            $result       = json_decode( trim( $error_output ), true );
            if ( empty( $result ) ) {
                $result = $json_parse_failure;
            }
        }
    }

    delete_transient( $transient );

    if ( true !== $result ) {

        // Roll-back file change.
        file_put_contents( $real_file, $previous_content );
        if ( function_exists( 'opcache_invalidate' ) ) {
            opcache_invalidate( $real_file, true );
        }

        if ( ! isset( $result['message'] ) ) {
            $message = __( 'Something went wrong.' );
        } else {
            $message = $result['message'];
            unset( $result['message'] );
        }
        return new WP_Error( 'php_error', $message, $result );
    }
}