#19063: partially fix set_payload handling of non-ASCII string input.

This is a backward compatible partial fix, the complete fix requires raising
an error instead of accepting the invalid input, so the real fix is only
suitable for 3.4.

Lib/test/test_email/test_email.py

@@ -92,6 +92,38 @@ class TestMessageAPI(TestEmailBase):
         msg.set_payload('This is a string payload', charset)
         self.assertEqual(msg.get_charset().input_charset, 'iso-8859-1')
 
+    def test_set_payload_with_8bit_data_and_charset(self):
+        data = b'\xd0\x90\xd0\x91\xd0\x92'
+        charset = Charset('utf-8')
+        msg = Message()
+        msg.set_payload(data, charset)
+        self.assertEqual(msg['content-transfer-encoding'], 'base64')
+        self.assertEqual(msg.get_payload(decode=True), data)
+        self.assertEqual(msg.get_payload(), '0JDQkdCS\n')
+
+    def test_set_payload_with_non_ascii_and_charset_body_encoding_none(self):
+        data = b'\xd0\x90\xd0\x91\xd0\x92'
+        charset = Charset('utf-8')
+        charset.body_encoding = None # Disable base64 encoding
+        msg = Message()
+        msg.set_payload(data.decode('utf-8'), charset)
+        self.assertEqual(msg['content-transfer-encoding'], '8bit')
+        self.assertEqual(msg.get_payload(decode=True), data)
+
+    def test_set_payload_with_8bit_data_and_charset_body_encoding_none(self):
+        data = b'\xd0\x90\xd0\x91\xd0\x92'
+        charset = Charset('utf-8')
+        charset.body_encoding = None # Disable base64 encoding
+        msg = Message()
+        msg.set_payload(data, charset)
+        self.assertEqual(msg['content-transfer-encoding'], '8bit')
+        self.assertEqual(msg.get_payload(decode=True), data)
+
+    def test_set_payload_to_list(self):
+        msg = Message()
+        msg.set_payload([])
+        self.assertEqual(msg.get_payload(), [])
+
     def test_get_charsets(self):
         eq = self.assertEqual