Handle unparseable reference headers

2 files changed, 14 insertions, 1 deletions

diff --git a/kittystore/test/test_utils.py b/kittystore/test/test_utils.py
index 8fc0c8b..6b2eafa 100644
--- a/kittystore/test/test_utils.py
+++ b/kittystore/test/test_utils.py
@@ -19,6 +19,15 @@ class TestUtils(unittest.TestCase):
                 msg, "example-list", store)
         self.assertEqual(ref_id, "200704070053.46646.other.person@example.com")
 
+    def test_wrong_reply_to_format(self):
+        with open(get_test_file("wrong-in-reply-to-header.txt")) as email_file:
+            msg = email.message_from_file(email_file)
+        store = Mock()
+        store.get_message_by_id_from_list.return_value = None
+        ref_id, thread_id = kittystore.utils.get_ref_and_thread_id(
+                msg, "example-list", store)
+        self.assertEqual(ref_id, None)
+
     def test_non_ascii_payload(self):
         """utils.payload_to_unicode must handle non-ascii messages"""
         for enc in ["utf8", "iso8859"]:
diff --git a/kittystore/utils.py b/kittystore/utils.py
index 28a3e15..9ed0810 100644
--- a/kittystore/utils.py
+++ b/kittystore/utils.py
@@ -118,7 +118,11 @@ def get_ref_and_thread_id(message, list_name, store):
         ref_id = ref_id.split()[0].strip()
     else:
         ref_id = message.get("In-Reply-To")
-    ref_id = IN_BRACKETS_RE.match(ref_id).group(1)
+    ref_id = IN_BRACKETS_RE.match(ref_id)
+    if ref_id is None:
+        # Can't parse the reference
+        return None, None
+    ref_id = ref_id.group(1)
     # It's a reply, use the thread_id from the parent email
     ref_msg = store.get_message_by_id_from_list(list_name, ref_id)
     if ref_msg is None: