      result._c_node = c_node
      result._proxy_type = PROXY_ELEMENT_ITER
      registerProxy(result, PROXY_ELEMENT_ITER)
-@@ -959,31 +1005,66 @@
+@@ -959,31 +1003,72 @@
      c_node = tree.xmlNewDocComment(c_doc, text)
      return c_node
  

     cdef int xmlXIncludeProcess(xmlDoc* doc)
+    cdef int xmlXIncludeProcessTree(xmlNode* doc)
     
Index: src/lxml/xpath.pxd
===================================================================
--- src/lxml/xpath.pxd	(Revision 18810)
+++ src/lxml/xpath.pxd	(Arbeitskopie)
@@ -42,6 +42,9 @@
         tree.xmlNode* ancestor

+
+    def test_multiple_elementrees(self):
+        etree = self.etree
+
+        a = etree.Element('a')
+        b = etree.SubElement(a, 'b')
+
+        t = etree.ElementTree(a)
+        self.assertEquals(self._rootstring(t), '<a><b/></a>')
+
+        t1 = etree.ElementTree(a)
+        self.assertEquals(self._rootstring(t1), '<a><b/></a>')
+        self.assertEquals(self._rootstring(t),  '<a><b/></a>')
+
+        t2 = etree.ElementTree(b)
+        self.assertEquals(self._rootstring(t2), '<b/>')
+        self.assertEquals(self._rootstring(t1), '<a><b/></a>')
+        self.assertEquals(self._rootstring(t),  '<a><b/></a>')
+
     def _writeElement(self, element, encoding='us-ascii'):
         """Write out element for comparison.
         """
@@ -1579,6 +1597,9 @@
         self.assertEquals(expected, self._writeElement(element, encoding))
         self.assertEquals(expected, self._writeElementFile(element, encoding))
         
+    def _rootstring(self, tree):
+        return self.etree.tostring(tree.getroot()).replace(' ', '').replace('\n', '')
+
     def _check_element_tree(self, tree):
         self._check_element(tree.getroot())
         
@@ -1721,6 +1742,9 @@
         f = StringIO(text)
         return etree.parse(f)
     
+    def _rootstring(self, tree):
+        return etree.tostring(tree.getroot()).replace(' ', '').replace('\n', '')
+
 class ETreeOnlyTestCase(HelperTestCase):
     """Tests only for etree, not ElementTree"""
     etree = etree
@@ -1808,6 +1832,27 @@
             None,
             a[0].prefix)
 
