PHP Bugs: Confusing Non-Objects for Objects (Example G)

php_bugs_4g.php

<?php

function exchange_send_message_raw($context, $content)
{
  $location = "https://test.cotten.io/exchange/raw_message.php";
  $request = array('direction' => 1, // outgoing
                   'context'   => $context,
                   'content'   => json_encode($content));
  $message = null;
  
  try {
    $response = ProxyPostClient::request($location, $request);
    $response_obj = json_decode($response);
    
    if (empty($response_obj)) {
      throw new Exception('Empty response.');
    }
    
    if (!isset($response_obj->content)) {
      throw new Exception('Missing property: content in response');
    }
    
    $message = $response_obj->content;
  
    print_formatted_log("Exchange Response: Success");
    print_formatted_log(json_encode($response_obj));
    echo "\n";
  } catch (Exception $e) {
    print_formatted_log("Exchange Response: Error: " . $e->getMessage());
    print_formatted_log($response); // raw text response
    echo "\n";
  }

  return $message;
}