Switch to base64 for mails over 200 chars in line

This is done because Python's qp encoding can be a bit problematic with
line endings.

Also, bumping the line length limit to 200 makes the downloaded mboxes
readable with any sensible patches and is well below the RFC 5322 limit
of 998 characters.

The changes in checksums are due to emails not being qp-encoded.
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>

patchwork/tests/test_mboxviews.py

@@ -389,14 +389,14 @@ class MboxEncoding(TestCase):
         self.person = defaults.patch_author_person
         self.person.save()
 
-    def testQuotedPrintableIfLineOver78(self):
-        patch = self.create_patch("x", "y" * 79)
+    def testBase64IfLineOver200(self):
+        patch = self.create_patch("x", "y" * 201)
         response = self.client.get('/patch/%d/mbox/' % patch.id)
         self.assertContains(response,
-                            'Content-Transfer-Encoding: quoted-printable')
+                            'Content-Transfer-Encoding: base64')
 
-    def test7bitIfLine78orLess(self):
-        patch = self.create_patch("x", "y" * 78)
+    def test7bitIfLine200orLess(self):
+        patch = self.create_patch("x", "y" * 200)
         response = self.client.get('/patch/%d/mbox/' % patch.id)
         self.assertContains(response,
                             'Content-Transfer-Encoding: 7bit')

patchwork/tests/test_rest.py

@@ -249,23 +249,21 @@ class APITest(APITestBase):
             i += 1
 
     def testSeriesMbox(self):
-        # XXX: since Python 3 email module wrap header lines differently
         self.check_mbox("/series/%s/revisions/1/mbox/" % self.series.pk,
                         'for_each_-intel_-crtc-v2.mbox',
-                        'db5b40c95b673ce38102943eaa02de69')
+                        '6d59b59dbf751064408249e18401275f')
 
     def testMboxWithCoverLetter(self):
-        # XXX: since Python 3 email module wrap header lines differently
         self.check_mbox("/series/%s/revisions/1/mbox_with_cover/" %
                         self.series.pk,
                         'for_each_-intel_-crtc-v2.mbox',
-                        'dd990d02f7d744a0b3b067f1afa831a6')
+                        '826f03a224083df013a2b373459527a3')
 
     def testCoverLetterMbox(self):
         self.check_mbox("/series/%s/revisions/1/cover/" %
                         self.series.pk,
                         'for_each_-intel_-crtc-v2.mbox',
-                        'b8cc8c1d04434cb12110e2562a963de9')
+                        '462a3414aedd2710d3dfed8a651ecd10')
 
     def testMboxAndMboxWithCoverShouldBeIdenticalForSeriesWithNoCL(self):
         mbox = self.client.get('/api/1.0' +

patchwork/views/__init__.py

@@ -21,7 +21,7 @@ from __future__ import absolute_import
 
 import datetime
 import time
-from email.encoders import encode_7or8bit, encode_quopri
+from email.encoders import encode_7or8bit, encode_base64
 from email.header import Header
 from email.mime.nonmultipart import MIMENonMultipart
 from email.parser import HeaderParser
@@ -185,8 +185,8 @@ class PatchMbox(MIMENonMultipart):
                                   **{'charset': self.patch_charset})
         self.set_payload(_text.encode(self.patch_charset))
 
-        if max((len(line) for line in _text.splitlines()), default=0) > 78:
-            encode_quopri(self)
+        if max((len(line) for line in _text.splitlines()), default=0) > 200:
+            encode_base64(self)
         else:
             encode_7or8bit(self)