Fixed possible TypeError while sending multipart emails.

doc/CHANGES.rst

@@ -11,6 +11,8 @@ Zope 2.12.3 (unreleased)
 Bugs Fixed
 ++++++++++
 
+- Fixed possible TypeError while sending multipart emails.
+
 - Also look for ZEXP imports within the clienthome directory. This
   provides a place to put imports that won't be clobbered by buildout
   in a buildout-based Zope instance.

src/Products/MailHost/MailHost.py

@@ -417,6 +417,7 @@ def _mungeHeaders(messageText, mto=None, mfrom=None, subject=None,
         # we don't use get_content_type because that has a default
         # value of 'text/plain'
         mo.set_type(msg_type)
+    if not mo.is_multipart():
         charset_match = CHARSET_RE.search(mo['Content-Type'] or '')
         if charset and not charset_match:
             # Don't change the charset if already set
@@ -427,6 +428,20 @@ def _mungeHeaders(messageText, mto=None, mfrom=None, subject=None,
             # If a charset parameter was provided use it for header encoding below,
             # Otherwise, try to use the charset provided in the message.
             charset = charset_match.groups()[0]
+    else:
+        # Do basically the same for each payload as for the complete
+        # multipart message.
+        for index, payload in enumerate(mo.get_payload()):
+            if not isinstance(payload, Message):
+                payload = message_from_string(payload)
+            charset_match = CHARSET_RE.search(payload['Content-Type'] or '')
+            if payload.get_filename() is None:
+                # No binary file
+                if charset and not charset_match:
+                    payload.set_charset(charset)
+                elif charset_match and not charset:
+                    charset = charset_match.groups()[0]
+            mo.get_payload()[index] = payload
 
     # Parameters given will *always* override headers in the messageText.
     # This is so that you can't override or add to subscribers by adding

src/Products/MailHost/tests/testMailHost.py

@@ -518,6 +518,92 @@ A M\xc3\xa9ssage""")
                                        statusTemplate='check_status')
         self.failUnlessEqual(result, 'Message Sent')
 
+    def testSendMultiPartAlternativeMessage(self):
+        msg = ("""\
+Content-Type: multipart/alternative; boundary="===============0490954888=="
+MIME-Version: 1.0
+Date: Sun, 27 Aug 2006 17:00:00 +0200
+Subject: My multipart email
+To: Foo Bar <foo@domain.com>
+From: sender@domain.com
+
+--===============0490954888==
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: quoted-printable
+
+This is plain text.
+--===============0490954888==
+Content-Type: text/html; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: quoted-printable
+
+<p>This is html.</p>
+--===============0490954888==--
+""")
+
+        mailhost = self._makeOne('MailHost')
+        # Specifying a charset for the header may have unwanted side
+        # effects in the case of multipart mails.
+        # (TypeError: expected string or buffer)
+        mailhost.send(msg, charset='utf-8')
+        self.assertEqual(mailhost.sent, msg)
+
+    def testSendMultiPartMixedMessage(self):
+        msg = ("""\
+Content-Type: multipart/mixed; boundary="XOIedfhf+7KOe/yw"
+Content-Disposition: inline
+MIME-Version: 1.0
+Date: Sun, 27 Aug 2006 17:00:00 +0200
+Subject: My multipart email
+To: Foo Bar <foo@domain.com>
+From: sender@domain.com
+
+--XOIedfhf+7KOe/yw
+Content-Type: text/plain; charset=us-ascii
+Content-Disposition: inline
+
+This is a test with as attachment OFS/www/new.gif.
+
+--XOIedfhf+7KOe/yw
+Content-Type: image/gif
+Content-Disposition: attachment; filename="new.gif"
+Content-Transfer-Encoding: base64
+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==
+
+--XOIedfhf+7KOe/yw
+Content-Type: text/plain; charset=iso-8859-1
+Content-Disposition: attachment; filename="test.txt"
+Content-Transfer-Encoding: quoted-printable
+
+D=EDt =EFs =E9=E9n test
+
+--XOIedfhf+7KOe/yw--
+""")
+
+        mailhost = self._makeOne('MailHost')
+        # Specifying a charset for the header may have unwanted side
+        # effects in the case of multipart mails.
+        # (TypeError: expected string or buffer)
+        mailhost.send(msg, charset='utf-8')
+        self.assertEqual(mailhost.sent, msg)
+
 
 def test_suite():
     suite = unittest.TestSuite()