[FIX] P3: fix base64 and StringIO uses

* StringIO removed from stdlib, replace with io
* try to correctly handle BytesIO/StringIO (one is for bytes the other
  is for text)
* fix base64: Python 3 removed bytes-encoding and bytes-bytes
  codecs (via #encode) so replace all calls to str.encode('base64'),
  also b64encode is a bytes->bytes conversion so attempt to properly
  handle that

issue #8530

3 files changed, 8 insertions, 7 deletions

diff --git a/addons/mail/tests/test_mail_features.py b/addons/mail/tests/test_mail_features.py
index 92613f55e51..a6fce59c10a 100644
--- a/addons/mail/tests/test_mail_features.py
+++ b/addons/mail/tests/test_mail_features.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
+import base64
 
 from odoo.addons.mail.tests.common import TestMail
 from odoo.addons.mail.tests.test_mail_gateway import MAIL_TEMPLATE_PLAINTEXT
@@ -89,8 +90,8 @@ class TestMessagePost(TestMail):
         _body, _body_alt = '<p>Test Body</p>', 'Test Body'
         _subject = 'Test Subject'
         _attachments = [
-            ('List1', 'My first attachment'),
-            ('List2', 'My second attachment')
+            ('List1', b'My first attachment'),
+            ('List2', b'My second attachment')
         ]
         _attach_1 = self.env['ir.attachment'].sudo(self.user_employee).create({
             'name': 'Attach1', 'datas_fname': 'Attach1',
@@ -129,7 +130,7 @@ class TestMessagePost(TestMail):
                          'message_post: all atttachments should be linked to the mail.test model')
         self.assertEqual(set(msg.attachment_ids.mapped('res_id')), set([self.test_pigs.id]),
                          'message_post: all atttachments should be linked to the pigs group')
-        self.assertEqual(set([x.decode('base64') for x in msg.attachment_ids.mapped('datas')]),
+        self.assertEqual(set([base64.b64decode(x) for x in msg.attachment_ids.mapped('datas')]),
                          set(['migration test', _attachments[0][1], _attachments[1][1]]))
         self.assertTrue(set([_attach_1.id, _attach_2.id]).issubset(msg.attachment_ids.ids),
                         'message_post: mail.message attachments duplicated')
diff --git a/addons/mail/tests/test_mail_message.py b/addons/mail/tests/test_mail_message.py
index db6dc9457a5..566a038d9ef 100644
--- a/addons/mail/tests/test_mail_message.py
+++ b/addons/mail/tests/test_mail_message.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
-
+import base64
 import itertools
 
 from odoo.addons.mail.tests.common import TestMail
@@ -215,7 +215,7 @@ class TestMailMessageAccess(TestMail):
 
     def test_mail_message_access_read_notification(self):
         attachment = self.env['ir.attachment'].create({
-            'datas': 'My attachment'.encode('base64'),
+            'datas': base64.b64encode(b'My attachment'),
             'name': 'doc.txt',
             'datas_fname': 'doc.txt'})
         # attach the attachment to the message
diff --git a/addons/mail/tests/test_mail_template.py b/addons/mail/tests/test_mail_template.py
index 60df04f0654..e5da1c628ae 100644
--- a/addons/mail/tests/test_mail_template.py
+++ b/addons/mail/tests/test_mail_template.py
@@ -17,13 +17,13 @@ class TestMailTemplate(TestMail):
             'name': '_Test_First',
             'datas_fname':
             'first.txt',
-            'datas': base64.b64encode('My first attachment'),
+            'datas': base64.b64encode(b'My first attachment'),
             'res_model': 'res.partner',
             'res_id': self.user_admin.partner_id.id
         }, {
             'name': '_Test_Second',
             'datas_fname': 'second.txt',
-            'datas': base64.b64encode('My second attachment'),
+            'datas': base64.b64encode(b'My second attachment'),
             'res_model': 'res.partner',
             'res_id': self.user_admin.partner_id.id
         }]