* Patch the PayPal Client request() method to capture arguments once * and avoid re-capturing them on retry.

PayPal Client request.php

<?php
/**
 * Patch the PayPal Client request() method to capture arguments once
 * and avoid re-capturing them on retry.
 *
 * Requires the runkit or runkit7 extension.
 */
add_action( 'plugins_loaded', function() {
    if ( ! function_exists( 'runkit_method_redefine' ) ) {
        error_log( 'Runkit extension is not available; PayPal Client patch was not applied.' );
        return;
    }

    // Redefine the "request" method of the Client class.
    runkit_method_redefine(
        'TEC\Tickets\Commerce\Gateways\PayPal\Client',
        'request',
        '$method, $url, array $query_args = array(), array $request_arguments = array(), $raw = false, $retries = 0',
        <<<'EOD'
            // Capture the arguments the first time this method is called.
            $arguments = array($method, $url, $query_args, $request_arguments, $raw, $retries);
            $method = strtoupper($method);

            // If $url is not a full URL, append query args.
            $url = 0 !== strpos($url, 'https://')
                ? $this->get_api_url($url, $query_args)
                : add_query_arg($query_args, $url);

            $default_arguments = [
                'headers' => [
                    'Accept'        => 'application/json',
                    'Authorization' => sprintf('Bearer %1$s', $this->get_access_token()),
                    'Content-Type'  => 'application/json',
                ]
            ];

            // For non-GET requests, ensure a body exists.
            if ('GET' !== $method) {
                $default_arguments['body'] = [];
            }

            foreach ($default_arguments as $key => $default_argument) {
                $request_arguments[$key] = array_merge($default_argument, \Tribe__Utils__Array::get($request_arguments, $key, []));
            }

            if ('GET' !== $method) {
                $content_type = \Tribe__Utils__Array::get($request_arguments, ['headers', 'Content-Type']);
                if (empty($content_type)) {
                    $content_type = \Tribe__Utils__Array::get($request_arguments, ['headers', 'content-type']);
                }
                // If body is present and content type is JSON, encode it.
                if (!empty($request_arguments['body']) && 'application/json' === strtolower($content_type)) {
                    $request_arguments['body'] = wp_json_encode($request_arguments['body']);
                }
            }

            // Execute the request.
            if ('GET' === $method) {
                $response = wp_remote_get($url, $request_arguments);
            } elseif ('POST' === $method) {
                $response = wp_remote_post($url, $request_arguments);
            } else {
                $request_arguments['method'] = $method;
                $response = wp_remote_request($url, $request_arguments);
            }

            if (is_wp_error($response)) {
                tribe('logger')->log_error(sprintf(
                    '[%s] PayPal "%s" request error: %s',
                    $method,
                    $url,
                    $response->get_error_message()
                ), 'tickets-commerce-paypal');
                return $response;
            }

            if (true === $raw) {
                return $response;
            }

            $response_code = wp_remote_retrieve_response_code($response);

            // Store the debug header if available.
            $this->set_debug_header(null);
            if (!empty($response['headers']['Paypal-Debug-Id'])) {
                $this->set_debug_header($response['headers']['Paypal-Debug-Id']);
            }

            // On 401 error (and not for token generation), retry once.
            if (
                401 === $response_code &&
                2 >= $retries &&
                false === strpos($url, 'v1/oauth2/token')
            ) {
                $merchant   = tribe(Merchant::class);
                $token_data = $this->get_access_token_from_client_credentials($merchant->get_client_id(), $merchant->get_client_secret());
                $saved      = $merchant->save_access_token_data($token_data);
                if ($saved) {
                    // Use the previously captured $arguments,
                    // update the retry count and re-call the method.
                    array_pop($arguments);
                    $arguments[] = $retries + 1;
                    return call_user_func_array([$this, 'request'], $arguments);
                }
            }

            // Decode the response body.
            $response_body = wp_remote_retrieve_body($response);
            $response_body = @json_decode($response_body, true);
            if (empty($response_body)) {
                return $response;
            }

            if (!is_array($response_body)) {
                tribe('logger')->log_error(sprintf('[%s] Unexpected PayPal %s response', $url, $method), 'tickets-commerce-paypal');
                return new \WP_Error('tec-tickets-commerce-gateway-paypal-client-unexpected', null, [
                    'method'            => $method,
                    'url'               => $url,
                    'query_args'        => $query_args,
                    'request_arguments' => $request_arguments,
                    'response'          => $response,
                ]);
            }

            return $response_body;
EOD
    );
} );