bpo-41402: Fix email ContentManager calling .encode() on bytes (GH-21631)
diff --git a/Lib/email/contentmanager.py b/Lib/email/contentmanager.py
index b91fb0e..3cf62dc 100644
--- a/Lib/email/contentmanager.py
+++ b/Lib/email/contentmanager.py
@@ -238,9 +238,7 @@ def set_bytes_content(msg, data, maintype, subtype, cte='base64',
data = binascii.b2a_qp(data, istext=False, header=False, quotetabs=True)
data = data.decode('ascii')
elif cte == '7bit':
- # Make sure it really is only ASCII. The early warning here seems
- # worth the overhead...if you care write your own content manager :).
- data.encode('ascii')
+ data = data.decode('ascii')
elif cte in ('8bit', 'binary'):
data = data.decode('ascii', 'surrogateescape')
msg.set_payload(data)
diff --git a/Lib/test/test_email/test_contentmanager.py b/Lib/test/test_email/test_contentmanager.py
index f4f6bb7..694cef4 100644
--- a/Lib/test/test_email/test_contentmanager.py
+++ b/Lib/test/test_email/test_contentmanager.py
@@ -776,6 +776,18 @@ def test_set_non_ascii_filename(self):
foo
""").encode('ascii'))
+ def test_set_content_bytes_cte_7bit(self):
+ m = self._make_message()
+ m.set_content(b'ASCII-only message.\n',
+ maintype='application', subtype='octet-stream', cte='7bit')
+ self.assertEqual(str(m), textwrap.dedent("""\
+ Content-Type: application/octet-stream
+ Content-Transfer-Encoding: 7bit
+ MIME-Version: 1.0
+
+ ASCII-only message.
+ """))
+
content_object_params = {
'text_plain': ('content', ()),
'text_html': ('content', ('html',)),
diff --git a/Misc/NEWS.d/next/Library/2020-07-26-18-17-30.bpo-41402.YRkVkp.rst b/Misc/NEWS.d/next/Library/2020-07-26-18-17-30.bpo-41402.YRkVkp.rst
new file mode 100644
index 0000000..45585a4
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-07-26-18-17-30.bpo-41402.YRkVkp.rst
@@ -0,0 +1 @@
+Fix :meth:`email.message.EmailMessage.set_content` when called with binary data and ``7bit`` content transfer encoding.
