Handle empty References tag

2 files changed, 38 insertions, 2 deletions

diff --git a/kittystore/test/test_utils.py b/kittystore/test/test_utils.py
index d097789..7662e81 100644
--- a/kittystore/test/test_utils.py
+++ b/kittystore/test/test_utils.py
@@ -33,6 +33,41 @@ class TestUtils(unittest.TestCase):
                 msg, "example-list", store)[0]
         self.assertEqual(ref_id, None)
 
+    def test_single_reference(self):
+        msg = Message()
+        msg["From"] = "dummy@example.com"
+        msg["Message-ID"] = "<dummy>"
+        msg["References"] = " <ref-1> "
+        msg.set_payload("Dummy message")
+        store = Mock()
+        ref_id = kittystore.utils.get_ref_and_thread_id(
+                msg, "example-list", store)[0]
+        self.assertEqual(ref_id, "ref-1")
+
+    def test_multiple_reference(self):
+        msg = Message()
+        msg["From"] = "dummy@example.com"
+        msg["Message-ID"] = "<dummy>"
+        msg["References"] = " <ref-1> <ref-2> "
+        msg.set_payload("Dummy message")
+        store = Mock()
+        ref_id = kittystore.utils.get_ref_and_thread_id(
+                msg, "example-list", store)[0]
+        self.assertEqual(ref_id, "ref-1")
+
+    def test_empty_reference(self):
+        msg = Message()
+        msg["From"] = "dummy@example.com"
+        msg["Message-ID"] = "<dummy>"
+        msg["References"] = " "
+        msg.set_payload("Dummy message")
+        store = Mock()
+        try:
+            kittystore.utils.get_ref_and_thread_id(
+                    msg, "example-list", store)
+        except IndexError, e:
+            self.fail("Empty 'References' tag should be handled")
+
     def test_non_ascii_headers(self):
         """utils.header_to_unicode must handle non-ascii headers"""
         testdata = [
diff --git a/kittystore/utils.py b/kittystore/utils.py
index 913b229..badf5af 100644
--- a/kittystore/utils.py
+++ b/kittystore/utils.py
@@ -111,12 +111,13 @@ def get_ref_and_thread_id(message, list_name, store):
         return None, None
     # It's a reply, use the thread_id from the parent email
     ref_id = message.get("References")
-    if ref_id is not None:
+    if ref_id is not None and ref_id.strip():
         # There can be multiple references, use the first one
         ref_id = ref_id.split()[0].strip()
     else:
         ref_id = message.get("In-Reply-To")
-    ref_id = IN_BRACKETS_RE.match(ref_id)
+    if ref_id is not None:
+        ref_id = IN_BRACKETS_RE.match(ref_id)
     if ref_id is None:
         # Can't parse the reference
         return None, None