Description:
------------
When using // at the beginning of an xpath-query, not only the children of the current SimpleXMLElement are searched (as stated in the manual), but the whole XML document instead.
(So, actually, it might only be a documentation issue...)

If this is expected behaviour, how is one supposed to search all <bar> elements, no whether where they are - but only under the current item (whatever it might be)?

Reproduce code:
---------------
<?php
$xmlstr = <<<XML
<?xml version='1.0' standalone='yes'?>
<root>
 <foo id="foo_1">
  <node>
   <bar>1</bar>
   <bar>2</bar>
  </node>
 </foo>
 <foo id="foo_2">
  <node>
   <bar>3</bar>
   <bar>4</bar>
  </node>
 </foo>
</root>
XML;

$xml = new SimpleXMLElement($xmlstr);

$foo_list = $xml->xpath('//foo');
$foo = $foo_list[0]; // now we have the node with id="foo_1"

$bar_list = $foo->xpath('//bar');
foreach($bar_list as $this_bar)
	echo "$this_bar ";
?>

Expected result:
----------------
1 2 

Actual result:
--------------
1 2 3 4