eZContentObjectTreeNode::subTreeByNodeID generate slow mysql query.

when you do :

$param = array( 'Depth' => '1',
'AttributeFilter' => array(....)
);
eZContentObjectTreeNode::subTreeByNodeID($param, $nodeid);

the code will generate a SQL query like
SELECT .... WHERE ezcontentobject_tree.path_string like '/1/2/278926/286968/286972/%' and ezcontentobject_tree.depth <= 5 and ...

the SQL should be :
SELECT .... WHERE ezcontentobject_tree.parent_node_id =286972 and ...

In the function ezContentObjecttreenode::createPathConditionAndNotEqParentSQLStrings
setting the default value 'le' to $depthOperator should resolve the pb and won,'t change anything (the value le is set bug a bit later
01362 $sqlDepthOperator = '<='; )