title: PHP error_log() working only if called directly and with full parameters
body: <p>I'm in the process of making an app I write for my company more professional.
  Until now, I always displayed all errors and simply tested the application so much that no errors won't occur anymore. If they still would, people would have to be able tell me the error message.</p>
  
  <p>As the client base is growing a lot (affiliated companies also wanting to use the app), I cannot do this any longer. So I looked for a way to log error messages instead of displaying them.</p>
  
  <p>This is what I'm using:</p>
  
  <pre><code>error_reporting(E_ALL);
  ini_set('display_errors', 1);
  ini_set("log_errors", 1); 
  ini_set("error_log", "logs/php-error.log");
  </code></pre>
  
  <p>1) <code>undefined_function();</code> // resulting error doesn't get logged</p>
  
  <p>2) <code>error_log( "user call without parameters" );</code> // doesn't get logged</p>
  
  <p>3) <code>error_log( "user call with explicit parameters", 3, "logs/php-error.log")</code> // gets logged</p>
  
  <p>4) <code>error_log( "user call with explicit parameters", 1, "admin@company.com")</code> // sends mail as expected</p>
  
  <p>Does anyone have a clue why <em>1)</em> and 2) don't work, but 3) and 4) do?
  I made sure the folder and file have 777-permission on the server.</p>
  
  <p>It is an nginx server by the way, and I don't have direct access to its configuration. With the correct hints, I may convince the admin to make the changes though.</p>
  
  <p>Thanks in advance.</p>
  
  <p>NEWS</p>
  
  <p>I just found this line in phpinfo:
  <code>error_log: /var/log/php-fpm/helpdesk-error.log</code></p>
  
  <p>This means the server overrides my value or simply ignores it, right? How do I change this behaviour?</p>