Fix #217: Fully remove element in removeChild in etree treebuilder (#259)

This adds a test here because we still fail the upstream one, as
our implementation of AAA is outdated.

Author: gsnedders

html5lib/tests/test_parser2.py

@@ -7,7 +7,7 @@
 from . import support  # noqa
 
 from html5lib.constants import namespaces
-from html5lib import parse, HTMLParser
+from html5lib import parse, parseFragment, HTMLParser
 
 
 # tests that aren't autogenerated from text files
@@ -88,3 +88,8 @@ def test_debug_log():
             expected[i] = tuple(log)
 
     assert parser.log == expected
+
+
+def test_no_duplicate_clone():
+    frag = parseFragment("<b><em><foo><foob><fooc><aside></b></em>")
+    assert len(frag) == 2

html5lib/treebuilders/etree.py

@@ -100,6 +100,7 @@ def insertBefore(self, node, refNode):
             node.parent = self
 
         def removeChild(self, node):
+            self._childNodes.remove(node)
             self._element.remove(node._element)
             node.parent = None