fix: start to reconcile internal inconsistencies wrt multiple from va…

…lues (#7935)

ietf/utils/mail.py

@@ -92,7 +92,17 @@ def send_smtp(msg, bcc=None):
     '''
     mark = time.time()
     add_headers(msg)
-    (fname, frm) = parseaddr(msg.get('From'))
+    # N.B. We have a disconnect with most of this code assuming a From header value will only
+    # have one address.
+    # The frm computed here is only used as the envelope from. 
+    # Previous code simply ran `parseaddr(msg.get('From'))`, getting lucky if the string returned
+    # from the get had more than one address in it. Python 3.9.20 changes the behavior of parseaddr
+    # and that erroneous use of the function no longer gets lucky.
+    # For the short term, to match behavior to date as closely as possible, if we get a message
+    # that has multiple addresses in the From header, we will use the first for the envelope from
+    from_tuples = getaddresses(msg.get_all('From', [settings.DEFAULT_FROM_EMAIL]))
+    assertion('len(from_tuples)==1', note=f"send_smtp received multiple From addresses: {from_tuples}")
+    _ , frm = from_tuples[0]
     addrlist = msg.get_all('To') + msg.get_all('Cc', [])
     if bcc:
         addrlist += [bcc]
@@ -446,6 +456,8 @@ def parse_preformatted(preformatted, extra=None, override=None):
         values = msg.get_all(key, [])
         if values:
             values = getaddresses(values)
+            if key=='From':
+                assertion('len(values)<2', note=f'parse_preformatted is constructing a From with multiple values: {values}')
             del msg[key]
             msg[key] = ',\n    '.join(formataddr(v) for v in values)
     for key in ['Subject', ]:

ietf/utils/tests.py

@@ -53,7 +53,7 @@ class SendingMail(TestCase):
 
     def test_send_mail_preformatted(self):
         msg = """To: [email protected], [email protected]
-From: [email protected], [email protected]
+From: [email protected]
 Cc: [email protected], [email protected]
 Bcc: [email protected], [email protected]
 Subject: subject
@@ -63,37 +63,37 @@ def test_send_mail_preformatted(self):
         send_mail_preformatted(None, msg, {}, {})
         recv = outbox[-1]
         self.assertSameEmail(recv['To'], '<[email protected]>, <[email protected]>')
-        self.assertSameEmail(recv['From'], '[email protected], [email protected]')
+        self.assertSameEmail(recv['From'], '[email protected]')
         self.assertSameEmail(recv['Cc'], '[email protected], [email protected]')
         self.assertSameEmail(recv['Bcc'], None)
         self.assertEqual(recv['Subject'], 'subject')
         self.assertEqual(get_payload_text(recv), 'body\n')
 
         override = {
             'To': '[email protected], [email protected]',
-            'From': '[email protected], [email protected]',
+            'From': '[email protected]',
             'Cc': '[email protected], [email protected]',
             'Subject': 'osubject',
         }
         send_mail_preformatted(request=None, preformatted=msg, extra={}, override=override)
         recv = outbox[-1]
         self.assertSameEmail(recv['To'], '<[email protected]>, <[email protected]>')
-        self.assertSameEmail(recv['From'], '[email protected], [email protected]')
+        self.assertSameEmail(recv['From'], '[email protected]')
         self.assertSameEmail(recv['Cc'], '[email protected], [email protected]')
         self.assertSameEmail(recv['Bcc'], None)
         self.assertEqual(recv['Subject'], 'osubject')
         self.assertEqual(recv.get_payload(), 'body\n')
 
         override = {
             'To': ['<[email protected]>', '[email protected]'],
-            'From': ['<[email protected]>', '[email protected]'],
+            'From': ['<[email protected]>'],
             'Cc': ['<[email protected]>', '[email protected]'],
             'Subject': 'osubject',
         }
         send_mail_preformatted(request=None, preformatted=msg, extra={}, override=override)
         recv = outbox[-1]
         self.assertSameEmail(recv['To'], '<[email protected]>, <[email protected]>')
-        self.assertSameEmail(recv['From'], '<[email protected]>, [email protected]')
+        self.assertSameEmail(recv['From'], '<[email protected]>')
         self.assertSameEmail(recv['Cc'], '<[email protected]>, [email protected]')
         self.assertSameEmail(recv['Bcc'], None)
         self.assertEqual(recv['Subject'], 'osubject')