Fixing issue, checking if elements by tag name have at least 1 element

src/pylast/__init__.py

@@ -1153,8 +1153,11 @@ class _BaseObject:
     def _extract_cdata_from_request(self, method_name, tag_name, params):
         doc = self._request(method_name, True, params)
 
-        first_child = doc.getElementsByTagName(tag_name)[0].firstChild
+        elements = doc.getElementsByTagName(tag_name)
+        if len(elements) == 0:
+            return None
 
+        first_child = elements[0].firstChild
         if first_child is None:
             return None
 

tests/test_network.py

@@ -417,3 +417,15 @@ class TestPyLastNetwork(TestPyLastWithLastFm):
 
         # Assert
         assert int(total) > 10000
+
+    def test_mbid_biography_issue(self):
+        # Arrange
+        mbid = "e2bef0c5-02e7-4505-b87f-90fc96bd70c3"
+
+        # Act
+        artist = self.network.get_artist_by_mbid(mbid)
+
+        # Assert
+        assert isinstance(artist, pylast.Artist)
+        assert artist.name == "Space 92"
+        assert artist.get_bio_content() is None