[Python-checkins] cpython: #21815: violate IMAP RFC to be compatible with, e.g., gmail
r.david.murray
python-checkins at python.org
Sat Jan 2 17:20:01 EST 2016
https://hg.python.org/cpython/rev/54b36229021a
changeset: 99760:54b36229021a
user: R David Murray <rdmurray at bitdance.com>
date: Sat Jan 02 17:18:34 2016 -0500
summary:
#21815: violate IMAP RFC to be compatible with, e.g., gmail
and others, including imaplib's own behavior. I'm applying this only to 3.6
because there's a potential backward compatibility concern: if there are
servers that include ] characters in the 'text' portion of their imap
responses, this code change could introduce a new bug.
Patch by Lita Cho, reviewed by Jessica McKellar, Berker Peksag, Maciej Szulik,
silentghost, and me (I fleshed out the comments with the additional
info/concerns.)
files:
Doc/library/imaplib.rst | 11 ++++++
Lib/imaplib.py | 10 +++++-
Lib/test/test_imaplib.py | 49 ++++++++++++++++++++++++++++
Misc/NEWS | 4 ++
4 files changed, 73 insertions(+), 1 deletions(-)
diff --git a/Doc/library/imaplib.rst b/Doc/library/imaplib.rst
--- a/Doc/library/imaplib.rst
+++ b/Doc/library/imaplib.rst
@@ -500,6 +500,17 @@
M.store(num, '+FLAGS', '\\Deleted')
M.expunge()
+ .. note::
+
+ Creating flags containing ']' (for example: "[test]") violates
+ :rfc:`3501` (the IMAP protocol). However, imaplib has historically
+ allowed creation of such tags, and popular IMAP servers, such as Gmail,
+ accept and produce such flags. There are non-Python programs which also
+ create such tags. Although it is an RFC violation and IMAP clients and
+ servers are supposed to be strict, imaplib nontheless continues to allow
+ such tags to be created for backward compatibility reasons, and as of
+ python 3.5.2/3.6.0, handles them if they are sent from the server, since
+ this improves real-world compatibility.
.. method:: IMAP4.subscribe(mailbox)
diff --git a/Lib/imaplib.py b/Lib/imaplib.py
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -111,7 +111,15 @@
# Literal is no longer used; kept for backward compatibility.
Literal = re.compile(br'.*{(?P<size>\d+)}$', re.ASCII)
MapCRLF = re.compile(br'\r\n|\r|\n')
-Response_code = re.compile(br'\[(?P<type>[A-Z-]+)( (?P<data>[^\]]*))?\]')
+# We no longer exclude the ']' character from the data portion of the response
+# code, even though it violates the RFC. Popular IMAP servers such as Gmail
+# allow flags with ']', and there are programs (including imaplib!) that can
+# produce them. The problem with this is if the 'text' portion of the response
+# includes a ']' we'll parse the response wrong (which is the point of the RFC
+# restriction). However, that seems less likely to be a problem in practice
+# than being unable to correctly parse flags that include ']' chars, which
+# was reported as a real-world problem in issue #21815.
+Response_code = re.compile(br'\[(?P<type>[A-Z-]+)( (?P<data>.*))?\]')
Untagged_response = re.compile(br'\* (?P<type>[A-Z-]+)( (?P<data>.*))?')
# Untagged_status is no longer used; kept for backward compatibility
Untagged_status = re.compile(
diff --git a/Lib/test/test_imaplib.py b/Lib/test/test_imaplib.py
--- a/Lib/test/test_imaplib.py
+++ b/Lib/test/test_imaplib.py
@@ -243,6 +243,55 @@
client.shutdown()
@reap_threads
+ def test_bracket_flags(self):
+
+ # This violates RFC 3501, which disallows ']' characters in tag names,
+ # but imaplib has allowed producing such tags forever, other programs
+ # also produce them (eg: OtherInbox's Organizer app as of 20140716),
+ # and Gmail, for example, accepts them and produces them. So we
+ # support them. See issue #21815.
+
+ class BracketFlagHandler(SimpleIMAPHandler):
+
+ def handle(self):
+ self.flags = ['Answered', 'Flagged', 'Deleted', 'Seen', 'Draft']
+ super().handle()
+
+ def cmd_AUTHENTICATE(self, tag, args):
+ self._send_textline('+')
+ self.server.response = yield
+ self._send_tagged(tag, 'OK', 'FAKEAUTH successful')
+
+ def cmd_SELECT(self, tag, args):
+ flag_msg = ' \\'.join(self.flags)
+ self._send_line(('* FLAGS (%s)' % flag_msg).encode('ascii'))
+ self._send_line(b'* 2 EXISTS')
+ self._send_line(b'* 0 RECENT')
+ msg = ('* OK [PERMANENTFLAGS %s \\*)] Flags permitted.'
+ % flag_msg)
+ self._send_line(msg.encode('ascii'))
+ self._send_tagged(tag, 'OK', '[READ-WRITE] SELECT completed.')
+
+ def cmd_STORE(self, tag, args):
+ new_flags = args[2].strip('(').strip(')').split()
+ self.flags.extend(new_flags)
+ flags_msg = '(FLAGS (%s))' % ' \\'.join(self.flags)
+ msg = '* %s FETCH %s' % (args[0], flags_msg)
+ self._send_line(msg.encode('ascii'))
+ self._send_tagged(tag, 'OK', 'STORE completed.')
+
+ with self.reaped_pair(BracketFlagHandler) as (server, client):
+ code, data = client.authenticate('MYAUTH', lambda x: b'fake')
+ self.assertEqual(code, 'OK')
+ self.assertEqual(server.response, b'ZmFrZQ==\r\n')
+ client.select('test')
+ typ, [data] = client.store(b'1', "+FLAGS", "[test]")
+ self.assertIn(b'[test]', data)
+ client.select('test')
+ typ, [data] = client.response('PERMANENTFLAGS')
+ self.assertIn(b'[test]', data)
+
+ @reap_threads
def test_issue5949(self):
class EOFHandler(socketserver.StreamRequestHandler):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -128,6 +128,10 @@
Library
-------
+- Issue #21815: Accept ] characters in the data portion of imap responses,
+ in order to handle the flags with square brackets accepted and produced
+ by servers such as gmail.
+
- Issue #25447: fileinput now uses sys.stdin as-is if it does not have a
buffer attribute (restores backward compatibility).
--
Repository URL: https://hg.python.org/cpython
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