From 23e334b43047448be63db959ad896738c0e074d3 Mon Sep 17 00:00:00 2001
From: Ross Patterson <me@rpatterson.net>
Date: Tue, 20 Mar 2012 13:40:26 -0700
Subject: [PATCH] Workaround a Python 3.2.0 bug in handling emails with empty
 headers. Fixes #14.

---
 CHANGES.txt                | 6 ++++++
 pyramid_mailer/response.py | 2 ++
 pyramid_mailer/tests.py    | 6 ++++++
 3 files changed, 14 insertions(+)

diff --git a/CHANGES.txt b/CHANGES.txt
index be69ac9..ae1d9a4 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,9 @@
+0.7 (Unreleased)
+----------------
+
+- Workaround a Python 3.2.0 bug in handling emails with empty
+  headers.
+
 0.6 (2012-03-20)
 ----------------
 
diff --git a/pyramid_mailer/response.py b/pyramid_mailer/response.py
index c29b9d9..234de24 100644
--- a/pyramid_mailer/response.py
+++ b/pyramid_mailer/response.py
@@ -343,6 +343,8 @@ def to_message(mail):
         if k.lower() in encoding.ADDR_HEADERS:
             if is_nonstr_iter(value): # not a string
                 value = ", ".join(value)
+        if value == '':
+            continue
         out[k] = value
 
     out.extract_payload(mail)
diff --git a/pyramid_mailer/tests.py b/pyramid_mailer/tests.py
index 2c56241..650a14a 100644
--- a/pyramid_mailer/tests.py
+++ b/pyramid_mailer/tests.py
@@ -976,6 +976,12 @@ def test_no_ctype_no_parts(self):
         result = self._callFUT(mail)
         self.assertEqual(result.__class__, MIMEPart)
 
+    def test_empty_header(self):
+        mail = self._makeBase()
+        mail['To'] = ''
+        result = self._callFUT(mail)
+        self.assertFalse('To' in result)
+
 class TestMIMEPart(unittest.TestCase):
     def _makeOne(self, type, **params):
         from pyramid_mailer.response import MIMEPart