Convert the Scrubber test to a doctest, and fix Scrubber.py, but otherwise

don't modernize the Scrubber handler.

The is the last of the handler test conversions until we figure out what to do
with the Approve handler.  In a unified user database the semantics of this
are unclear.

1 files changed, 217 insertions, 0 deletions

diff --git a/Mailman/docs/scrubber.txt b/Mailman/docs/scrubber.txt
new file mode 100644
index 000000000..0e13f78a2
--- /dev/null
+++ b/Mailman/docs/scrubber.txt
@@ -0,0 +1,217 @@
+The scrubber
+============
+
+The scrubber is an integral part of Mailman, both in the normal delivery of
+messages and in components such as the archiver.  Its primary purpose is to
+scrub attachments from messages so that binary goop doesn't end up in an
+archive message.
+
+    >>> from Mailman.Handlers.Scrubber import process, save_attachment
+    >>> from Mailman.Message import Message
+    >>> from Mailman.configuration import config
+    >>> from Mailman.database import flush
+    >>> from email import message_from_string
+    >>> mlist = config.list_manager.create('_xtest@example.com')
+    >>> mlist.preferred_language = 'en'
+    >>> flush()
+
+Helper functions for getting the attachment data.
+
+    >>> import os, re
+    >>> def read_attachment(filename, remove=True):
+    ...     path = os.path.join(mlist.archive_dir(), filename)
+    ...     fp = open(path)
+    ...     try:
+    ...         data = fp.read()
+    ...     finally:
+    ...         fp.close()
+    ...     if remove:
+    ...         os.unlink(path)
+    ...     return data
+
+    >>> from urlparse import urlparse
+    >>> def read_url_from_message(msg):
+    ...     url = None
+    ...     for line in msg.get_payload().splitlines():
+    ...         mo = re.match('URL: <(?P<url>[^>]+)>', line)
+    ...         if mo:
+    ...             url = mo.group('url')
+    ...             break
+    ...     path = '/'.join(urlparse(url).path.split('/')[3:])
+    ...     return read_attachment(path)
+
+
+Saving attachments
+------------------
+
+The Scrubber handler exposes a function called save_attachments() which can be
+used to strip various types of attachments and store them in the archive
+directory.  This is a public interface used by components outside the normal
+processing pipeline.
+
+Site administrators can decide whether the scrubber should use the attachment
+filename suggested in the message's Content-Disposition: header or not.  If
+enabled, the filename will be used when this header attribute is present (yes,
+this is an unfortunate double negative).
+
+    >>> config.SCRUBBER_DONT_USE_ATTACHMENT_FILENAME = False
+    >>> msg = message_from_string("""\
+    ... Content-Type: image/gif; name="xtest.gif"
+    ... Content-Transfer-Encoding: base64
+    ... Content-Disposition: attachment; filename="xtest.gif"
+    ... 
+    ... R0lGODdhAQABAIAAAAAAAAAAACwAAAAAAQABAAACAQUAOw==
+    ... """, Message)
+    >>> save_attachment(mlist, msg, '')
+    '<http://www.example.com/pipermail/_xtest@example.com//xtest.gif>'
+    >>> data = read_attachment('xtest.gif')
+    >>> data[:6]
+    'GIF87a'
+    >>> len(data)
+    34
+
+Saving the attachment does not alter the original message.
+
+    >>> print msg.as_string()
+    Content-Type: image/gif; name="xtest.gif"
+    Content-Transfer-Encoding: base64
+    Content-Disposition: attachment; filename="xtest.gif"
+    <BLANKLINE>
+    R0lGODdhAQABAIAAAAAAAAAAACwAAAAAAQABAAACAQUAOw==
+
+The site administrator can also configure Mailman to ignore the
+Content-Disposition: filename.  This is the default for reasons described in
+the Defaults.py.in file.
+
+    >>> config.SCRUBBER_DONT_USE_ATTACHMENT_FILENAME = True
+    >>> msg = message_from_string("""\
+    ... Content-Type: image/gif; name="xtest.gif"
+    ... Content-Transfer-Encoding: base64
+    ... Content-Disposition: attachment; filename="xtest.gif"
+    ... 
+    ... R0lGODdhAQABAIAAAAAAAAAAACwAAAAAAQABAAACAQUAOw==
+    ... """, Message)
+    >>> save_attachment(mlist, msg, '')
+    '<http://www.example.com/pipermail/_xtest@example.com/.../attachment.gif>'
+    >>> data = read_attachment('xtest.gif')
+    Traceback (most recent call last):
+    IOError: [Errno ...] No such file or directory:
+        '.../archives/private/_xtest@example.com/xtest.gif'
+    >>> data = read_attachment('attachment.gif')
+    >>> data[:6]
+    'GIF87a'
+    >>> len(data)
+    34
+
+
+Scrubbing image attachments
+---------------------------
+
+When scrubbing image attachments, the original message is modified to include
+a reference to the attachment file as available through the on-line archive.
+
+    >>> msg = message_from_string("""\
+    ... MIME-Version: 1.0
+    ... Content-Type: multipart/mixed; boundary="BOUNDARY"
+    ...
+    ... --BOUNDARY
+    ... Content-type: text/plain; charset=us-ascii
+    ... 
+    ... This is a message.
+    ... --BOUNDARY
+    ... Content-Type: image/gif; name="xtest.gif"
+    ... Content-Transfer-Encoding: base64
+    ... Content-Disposition: attachment; filename="xtest.gif"
+    ... 
+    ... R0lGODdhAQABAIAAAAAAAAAAACwAAAAAAQABAAACAQUAOw==
+    ... --BOUNDARY--
+    ... """, Message)
+    >>> msgdata = {}
+
+The Scrubber.process() function is different than other handler process
+functions in that it returns the scrubbed message.
+
+    >>> scrubbed_msg = process(mlist, msg, msgdata)
+    >>> scrubbed_msg is msg
+    True
+    >>> print scrubbed_msg.as_string()
+    MIME-Version: 1.0
+    Message-ID: ...
+    Content-Type: text/plain; charset="us-ascii"
+    Content-Transfer-Encoding: 7bit
+    <BLANKLINE>
+    This is a message.
+    -------------- next part --------------
+    A non-text attachment was scrubbed...
+    Name: xtest.gif
+    Type: image/gif
+    Size: 34 bytes
+    Desc: not available
+    URL: <http://www.example.com/pipermail/_xtest@example.com/attachments/.../attachment.gif>
+    <BLANKLINE>
+
+This is the same as the transformed message originally passed in.
+
+    >>> print msg.as_string()
+    MIME-Version: 1.0
+    Message-ID: ...
+    Content-Type: text/plain; charset="us-ascii"
+    Content-Transfer-Encoding: 7bit
+    <BLANKLINE>
+    This is a message.
+    -------------- next part --------------
+    A non-text attachment was scrubbed...
+    Name: xtest.gif
+    Type: image/gif
+    Size: 34 bytes
+    Desc: not available
+    URL: <http://www.example.com/pipermail/_xtest@example.com/attachments/.../attachment.gif>
+    <BLANKLINE>
+    >>> msgdata
+    {}
+
+The URL will point to the attachment sitting in the archive.
+
+    >>> data = read_url_from_message(msg)
+    >>> data[:6]
+    'GIF87a'
+    >>> len(data)
+    34
+
+
+Scrubbing text attachments
+--------------------------
+
+Similar to image attachments, text attachments will also be scrubbed, but the
+placeholder will be slightly different.
+
+    >>> msg = message_from_string("""\
+    ... MIME-Version: 1.0
+    ... Content-Type: multipart/mixed; boundary="BOUNDARY"
+    ...
+    ... --BOUNDARY
+    ... Content-type: text/plain; charset=us-ascii; format=flowed; delsp=no
+    ...
+    ... This is a message.
+    ... --BOUNDARY
+    ... Content-type: text/plain; name="xtext.txt"
+    ... Content-Disposition: attachment; filename="xtext.txt"
+    ...
+    ... This is a text attachment.
+    ... --BOUNDARY--
+    ... """, Message)
+    >>> scrubbed_msg = process(mlist, msg, {})
+    >>> print scrubbed_msg.as_string()
+    MIME-Version: 1.0
+    Message-ID: ...
+    Content-Transfer-Encoding: 7bit
+    Content-Type: text/plain; charset="us-ascii"; format="flowed"; delsp="no"
+    <BLANKLINE>
+    This is a message.
+    -------------- next part --------------
+    An embedded and charset-unspecified text was scrubbed...
+    Name: xtext.txt
+    URL: <http://www.example.com/pipermail/_xtest@example.com/attachments/.../attachment.txt>
+    <BLANKLINE>
+    >>> read_url_from_message(msg)
+    'This is a text attachment.'