add note about using __FILE__ in a stub

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@259949 c90b9560-bf6c-de11-be94-00142212c4b1

reference/phar/Phar/running.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- $Revision: 1.1 $ -->
+<!-- $Revision: 1.2 $ -->
 <refentry xml:id="phar.running" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
  <refnamediv>
   <refname>Phar::running</refname>
@@ -18,6 +18,11 @@
    like the <literal>__FILE__</literal> magic constant, and only has effect inside
    an executing phar archive.
   </para>
+  <para>
+   Inside the stub of an archive, <function>Phar::running</function> returns
+   <literal>&quot;&quot;</literal>.  Simply use <constant>__FILE__</constant>
+   to access the current running phar inside a stub.
+  </para>
  </refsect1>
 
  <refsect1 role="parameters">