Added missing __len__ method that stopped html5lib tree builder from working on nested formatting elements. [bug=943246]

2 files changed, 5 insertions, 0 deletions

diff --git a/bs4/builder/_html5lib.py b/bs4/builder/_html5lib.py
index cf716df..b8c2bb6 100644
--- a/bs4/builder/_html5lib.py
+++ b/bs4/builder/_html5lib.py
@@ -107,6 +107,8 @@ class AttrList(object):
         return list(self.attrs.items())
     def keys(self):
         return list(self.attrs.keys())
+    def __len__(self):
+        return len(self.attrs)
     def __getitem__(self, name):
         return self.attrs[name]
     def __contains__(self, name):
diff --git a/bs4/testing.py b/bs4/testing.py
index 717e721..a3e0b38 100644
--- a/bs4/testing.py
+++ b/bs4/testing.py
@@ -132,6 +132,9 @@ class HTMLTreeBuilderSmokeTest(object):
         self.assertTrue(soup.br.is_empty_element)
         self.assertEqual(str(soup.br), "<br/>")
 
+    def test_nested_formatting_elements(self):
+        self.assertSoupEquals("<em><em></em></em>")
+
     def test_comment(self):
         # Comments are represented as Comment objects.
         markup = "<p>foo<!--foobar-->baz</p>"