[REF] mail,test_mail: prefer EmailMessage over deprecated Message

[PEP 594][1] is going to depreciate legacy `email.message.Message` API in
PY3.8 in favor `email.message.EmailMessage`.

All `email.message_from_x` constructor functions take an optional
`policy` argument. The policy can either be `policy.compat32` to
generate an `email.message.Message` instance, either be `policy.SMTP`
to generate an `email.message.EmailMessage` instance.

The [current][2] default policy is `policy.compat32` but will change in
a future version of python. It is recommended to always specify the
policy.

[1]: https://www.python.org/dev/peps/pep-0594/#email-legacy-api
[2] https://docs.python.org/3.7/library/email.parser.html#email.parser.BytesParser

3 files changed, 23 insertions, 17 deletions

diff --git a/addons/l10n_it_edi/models/ir_mail_server.py b/addons/l10n_it_edi/models/ir_mail_server.py
index 580635dfc3d..d4575c90fe1 100644
--- a/addons/l10n_it_edi/models/ir_mail_server.py
+++ b/addons/l10n_it_edi/models/ir_mail_server.py
@@ -6,6 +6,7 @@ import io
 import re
 import logging
 import email
+import email.policy
 import dateutil
 import pytz
 import base64
@@ -74,7 +75,7 @@ class FetchmailServer(models.Model):
                         message = bytes(message.data)
                     if isinstance(message, str):
                         message = message.encode('utf-8')
-                    msg_txt = email.message_from_bytes(message)
+                    msg_txt = email.message_from_bytes(message, policy=email.policy.SMTP)
 
                     try:
                         self._attachment_invoice(msg_txt)
diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 94ae2e4b448..15d5f882f0a 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -5,6 +5,7 @@ import base64
 import datetime
 import dateutil
 import email
+import email.policy
 import hashlib
 import hmac
 import lxml
@@ -20,7 +21,7 @@ except ImportError:
     import xmlrpclib
 
 from collections import namedtuple
-from email.message import Message
+from email.message import EmailMessage
 from email.utils import formataddr
 from lxml import etree
 from werkzeug import url_encode
@@ -876,8 +877,8 @@ class MailThread(models.AbstractModel):
 
         :raises: ValueError, TypeError
         """
-        if not isinstance(message, Message):
-            raise TypeError('message must be an email.message.Message at this point')
+        if not isinstance(message, EmailMessage):
+            raise TypeError('message must be an email.message.EmailMessage at this point')
         catchall_alias = self.env['ir.config_parameter'].sudo().get_param("mail.catchall.alias")
         bounce_alias = self.env['ir.config_parameter'].sudo().get_param("mail.bounce.alias")
         fallback_model = model
@@ -1093,7 +1094,7 @@ class MailThread(models.AbstractModel):
             message = bytes(message.data)
         if isinstance(message, str):
             message = message.encode('utf-8')
-        message = email.message_from_bytes(message)
+        message = email.message_from_bytes(message, policy=email.policy.SMTP)
 
         # parse the message, verify we are not in a loop by checking message_id is not duplicated
         msg_dict = self.message_parse(message, save_original=save_original)
@@ -1301,8 +1302,8 @@ class MailThread(models.AbstractModel):
         :param message_dict: dictionary holding already-parsed values and in
             which bounce-related values will be added;
         """
-        if not isinstance(email_message, Message):
-            raise TypeError('message must be an email.message.Message at this point')
+        if not isinstance(email_message, EmailMessage):
+            raise TypeError('message must be an email.message.EmailMessage at this point')
 
         email_part = next((part for part in email_message.walk() if part.get_content_type() == 'message/rfc822'), None)
         dsn_part = next((part for part in email_message.walk() if part.get_content_type() == 'message/delivery-status'), None)
@@ -1361,8 +1362,8 @@ class MailThread(models.AbstractModel):
                               ('file2', 'bytes')}
             }
         """
-        if not isinstance(message, Message):
-            raise ValueError(_('Message should be a valid Message instance'))
+        if not isinstance(message, EmailMessage):
+            raise ValueError(_('Message should be a valid EmailMessage instance'))
         msg_dict = {'message_type': 'email'}
 
         message_id = message.get('Message-Id')
diff --git a/addons/test_mail/tests/test_mail_gateway.py b/addons/test_mail/tests/test_mail_gateway.py
index 52ed239bc0e..ff7b3580559 100644
--- a/addons/test_mail/tests/test_mail_gateway.py
+++ b/addons/test_mail/tests/test_mail_gateway.py
@@ -2,6 +2,7 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 import email
+import email.policy
 import socket
 
 from email.utils import formataddr
@@ -17,6 +18,9 @@ from odoo.addons.test_mail.tests.common import mail_new_test_user
 from odoo.tests import tagged
 from odoo.tools import email_split_and_format, mute_logger, pycompat
 
+def from_string(text):
+    return email.message_from_string(pycompat.to_text(text), policy=email.policy.SMTP)
+
 
 @tagged('mail_gateway')
 class TestEmailParsing(BaseFunctionalTest, MockEmails):
@@ -24,16 +28,16 @@ class TestEmailParsing(BaseFunctionalTest, MockEmails):
     def test_message_parse_body(self):
         # test pure plaintext
         plaintext = self.format(test_mail_data.MAIL_TEMPLATE_PLAINTEXT, email_from='Sylvie Lelitre <test.sylvie.lelitre@agrolait.com>')
-        res = self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(plaintext)))
+        res = self.env['mail.thread'].message_parse(from_string(plaintext))
         self.assertIn('Please call me as soon as possible this afternoon!', res['body'])
 
         # test multipart / text and html -> html has priority
         multipart = self.format(MAIL_TEMPLATE, email_from='Sylvie Lelitre <test.sylvie.lelitre@agrolait.com>')
-        res = self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(multipart)))
+        res = self.env['mail.thread'].message_parse(from_string(multipart))
         self.assertIn('<p>Please call me as soon as possible this afternoon!</p>', res['body'])
 
         # test multipart / mixed
-        res = self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(test_mail_data.MAIL_MULTIPART_MIXED)))
+        res = self.env['mail.thread'].message_parse(from_string(test_mail_data.MAIL_MULTIPART_MIXED))
         self.assertNotIn(
             'Should create a multipart/mixed: from gmail, *bold*, with attachment', res['body'],
             'message_parse: text version should not be in body after parsing multipart/mixed')
@@ -41,7 +45,7 @@ class TestEmailParsing(BaseFunctionalTest, MockEmails):
             '<div dir="ltr">Should create a multipart/mixed: from gmail, <b>bold</b>, with attachment.<br clear="all"><div><br></div>', res['body'],
             'message_parse: html version should be in body after parsing multipart/mixed')
 
-        res = self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(test_mail_data.MAIL_MULTIPART_MIXED_TWO)))
+        res = self.env['mail.thread'].message_parse(from_string(test_mail_data.MAIL_MULTIPART_MIXED_TWO))
         self.assertNotIn('First and second part', res['body'],
                          'message_parse: text version should not be in body after parsing multipart/mixed')
         self.assertIn('First part', res['body'],
@@ -49,24 +53,24 @@ class TestEmailParsing(BaseFunctionalTest, MockEmails):
         self.assertIn('Second part', res['body'],
                       'message_parse: second part of the html version should be in body after parsing multipart/mixed')
 
-        res = self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(test_mail_data.MAIL_SINGLE_BINARY)))
+        res = self.env['mail.thread'].message_parse(from_string(test_mail_data.MAIL_SINGLE_BINARY))
         self.assertEqual(res['body'], '')
         self.assertEqual(res['attachments'][0][0], 'thetruth.pdf')
 
     def test_message_parse_eml(self):
         # Test that the parsing of mail with embedded emails as eml(msg) which generates empty attachments, can be processed.
         mail = self.format(test_mail_data.MAIL_EML_ATTACHMENT, email_from='Sylvie Lelitre <test.sylvie.lelitre@agrolait.com>', to='generic@test.com')
-        self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(mail)))
+        self.env['mail.thread'].message_parse(from_string(mail))
 
     def test_message_parse_plaintext(self):
         """ Incoming email in plaintext should be stored as html """
         mail = self.format(test_mail_data.MAIL_TEMPLATE_PLAINTEXT, email_from='Sylvie Lelitre <test.sylvie.lelitre@agrolait.com>', to='generic@test.com')
-        res = self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(mail)))
+        res = self.env['mail.thread'].message_parse(from_string(mail))
         self.assertIn('<pre>\nPlease call me as soon as possible this afternoon!\n\n--\nSylvie\n</pre>', res['body'])
 
     def test_message_parse_xhtml(self):
         # Test that the parsing of XHTML mails does not fail
-        self.env['mail.thread'].message_parse(email.message_from_string(pycompat.to_text(test_mail_data.MAIL_XHTML)))
+        self.env['mail.thread'].message_parse(from_string(test_mail_data.MAIL_XHTML))
 
 
 @tagged('mail_gateway')