fixing bug #15696

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@70872 c90b9560-bf6c-de11-be94-00142212c4b1

appendices/migration4.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.18 $ -->
+<!-- $Revision: 1.19 $ -->
  <appendix id="migration4">
   <title>Migrating from PHP 3 to PHP 4</title>
 	
@@ -423,6 +423,33 @@ php_admin_flag [PHP directive name] [On|Off]
    </para>
   </section>
 
+  <section id='migration4.variables'>
+   <title>Handling of global variables</title>
+   <para>
+    While handling of global variables had the focus on to be easy in
+    PHP3 and early versions of PHP4, the focus has changed to be more
+    secure. While in PHP3 following example worked fine, in PHP4 it
+    has to be unset($GLOBALS["id"]);. This is only one issue of global
+    variable handling. You should always have used $GLOBALS, with
+    newer versions of PHP4 you are forced to do so in most cases.
+   </para>
+   <example>
+    <programlisting role="php">
+<![CDATA[
+<?php
+$id=1;
+function test()
+{
+        global $id;
+	unset($id);
+}
+test();
+echo($id);
+]]>
+    </programlisting>
+   </example>
+  </section>
+
  </appendix>