Commit 836d475a authored by Claude Paroz's avatar Claude Paroz
Browse files

Fixed #22561 -- Prevented too long lines in email messages 

Thanks NotSqrt for the excellent report and Tim Graham for the review.
parent f43da05c

django/core/mail/message.py

+8 −1
Original line number Diff line number Diff line
@@ -25,11 +25,15 @@ from django.utils.encoding import force_text 
# some spam filters.

utf8_charset = Charset.Charset('utf-8')

utf8_charset.body_encoding = None  # Python defaults to BASE64

utf8_charset_qp = Charset.Charset('utf-8')

utf8_charset_qp.body_encoding = Charset.QP



# Default MIME type to use on attachments (if it is not explicitly given

# and cannot be guessed).

DEFAULT_ATTACHMENT_MIME_TYPE = 'application/octet-stream'



RFC5322_EMAIL_LINE_LENGTH_LIMIT = 998





class BadHeaderError(ValueError):

    pass
@@ -169,7 +173,10 @@ class SafeMIMEText(MIMEMixin, MIMEText): 
            # We do it manually and trigger re-encoding of the payload.

            MIMEText.__init__(self, _text, _subtype, None)

            del self['Content-Transfer-Encoding']

            self.set_payload(_text, utf8_charset)

            has_long_lines = any(len(l) > RFC5322_EMAIL_LINE_LENGTH_LIMIT for l in _text.splitlines())

            # Quoted-Printable encoding has the side effect of shortening long

            # lines, if any (#22561).

            self.set_payload(_text, utf8_charset_qp if has_long_lines else utf8_charset)

            self.replace_header('Content-Type', 'text/%s; charset="%s"' % (_subtype, _charset))

        elif _charset is None:

            # the default value of '_charset' is 'us-ascii' on Python 2

tests/mail/tests.py

+16 −0
Original line number Diff line number Diff line
@@ -639,6 +639,22 @@ class BaseEmailBackendTests(HeadersCheckMixin, object): 
        self.assertEqual(message["subject"], '=?utf-8?q?Ch=C3=A8re_maman?=')

        self.assertEqual(force_text(message.get_payload(decode=True)), 'Je t\'aime très fort')



    def test_send_long_lines(self):

        """

        Email line length is limited to 998 chars by the RFC:

        https://tools.ietf.org/html/rfc5322#section-2.1.1

        Message body containing longer lines are converted to Quoted-Printable

        to avoid having to insert newlines, which could be hairy to do properly.

        """

        email = EmailMessage('Subject', "Comment ça va? " * 100, 'from@example.com', ['to@example.com'])

        email.send()

        message = self.get_the_message()

        self.assertMessageHasHeaders(message, {

            ('MIME-Version', '1.0'),

            ('Content-Type', 'text/plain; charset="utf-8"'),

            ('Content-Transfer-Encoding', 'quoted-printable'),

        })



    def test_send_many(self):

        email1 = EmailMessage('Subject', 'Content1', 'from@example.com', ['to@example.com'])

        email2 = EmailMessage('Subject', 'Content2', 'from@example.com', ['to@example.com'])