document setlocale(LC_ALL, null) to retrieve current setting (#4765)

Author: remicollet

reference/strings/functions/setlocale.xml

@@ -11,7 +11,7 @@
   <methodsynopsis>
    <type class="union"><type>string</type><type>false</type></type><methodname>setlocale</methodname>
    <methodparam><type>int</type><parameter>category</parameter></methodparam>
-   <methodparam><type>string</type><parameter>locales</parameter></methodparam>
+   <methodparam><type class="union"><type>string</type><type>null</type></type><parameter>locales</parameter></methodparam>
    <methodparam rep="repeat"><type>string</type><parameter>rest</parameter></methodparam>
   </methodsynopsis>
   <simpara>Alternative signature (not supported with named arguments):</simpara>
@@ -102,7 +102,7 @@
        categories, or from "LANG".
       </para>
       <para>
-       If <parameter>locales</parameter> is <literal>"0"</literal>,
+       If <parameter>locales</parameter> is &null;,
        the locale setting is not affected, only the current setting is returned.
       </para>
       <para>
@@ -184,6 +184,21 @@ echo strftime("%A %e %B %Y", mktime(0, 0, 0, 12, 22, 1978));
 $loc_de = setlocale(LC_ALL, 'de_DE@euro', 'de_DE', 'de', 'ge');
 echo "Preferred locale for german on this system is '$loc_de'";
 ?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+  <para>
+   <example>
+    <title><function>setlocale</function> Retrieve current setting</title>
+    <programlisting role="php" annotations="non-interactive">
+<![CDATA[
+<?php
+/* Retrieve current setting */
+$current = setlocale(LC_ALL, null);
+
+echo "Current locale '$current'";
+?>
 ]]>
     </programlisting>
    </example>