improve coverage

tests/fixtures/xml_parser_simple_5.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<rss xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#" version="2.0">
+    <nochannel>
+        <item>
+            <title>Title 1</title>
+        </item>
+    </nochannel>
+</rss>

tests/test_xml_parser.py

@@ -31,7 +31,7 @@ def test_simple_2():
 
 
 def test_simple_3():
-    """Test parsing various actual XML files."""
+    """Test parsing XML file with invalid tags."""
     xml_parser = XmlParser()
     xml = load_fixture("xml_parser_simple_3.xml")
     feed = xml_parser.parse(xml)
@@ -50,6 +50,14 @@ def test_simple_4():
     assert feed.entries[0].title == "1"
 
 
+def test_simple_5():
+    """Test parsing XML file with invalid tags."""
+    xml_parser = XmlParser()
+    xml = load_fixture("xml_parser_simple_5.xml")
+    feed = xml_parser.parse(xml)
+    assert feed is None
+
+
 def test_complex_1():
     """Test parsing various actual XML files."""
     xml_parser = XmlParser()