Detect and never archive IMAP server pseudo mbox messages

IMAP servers (Dovecot and UW-IMAP at least) may store mailbox meta data for
mboxes in a pseudo message.  Such messages are now detected and never archived.

This commit includes a test case in the test suite.

CHANGELOG

@@ -51,6 +51,9 @@ Version 0.8.0   - UNRELEASED
     boolean constants).
   * Added a lot of test cases for maildir archiving to the test suite.
     Maildir testing should now be roughly on par with mbox testing.
+  * IMAP servers (Dovecot and UW-IMAP at least) may store mailbox meta data
+    for mboxes in a pseudo message.  Such messages are now detected and never
+    archived.  Obsoletes: patch #2210707.  (Thanks, "tlhackque")
 
 Version 0.7.2   - 9 November 2007
 

archivemail

@@ -1156,6 +1156,12 @@ def _archive_mbox(mailbox_name, final_archive_name):
     msg = original.next()
     if not msg and (original.starting_size > 0):
         user_error("'%s' is not a valid mbox-format mailbox" % mailbox_name)
+    if msg and 'X-IMAP' in msg:
+        # Dovecot and UW-IMAP pseudo message for mailbox meta data
+        vprint("detected IMAP pseudo message")
+        if retain:
+            retain.write(msg)
+        msg = original.next()
     while (msg):
         msg_size = sizeof_message(msg)
         stats.another_message(msg_size)

test_archivemail

@@ -1103,6 +1103,28 @@ class TestArchiveSize(unittest.TestCase):
         archivemail.options.min_size = None
 
 
+class TestXIMAPMessage(TestArchive):
+    """Test if IMAP pseudo messages in mboxes are properly handled."""
+    def setUp(self):
+        super(TestXIMAPMessage, self).setUp()
+        archivemail.options.quiet = True
+
+    def testXIMAPMbox(self):
+        """IMAP pseudo messages in an mbox are always preserved."""
+        self.good_mbox = make_mbox(hours_old=181*24, headers={'X-IMAP': 'dummytext'},
+                messages=1)
+        self.good_archive = make_mbox(hours_old=181*24, messages=3)
+        self.mbox = tempfile.mkstemp()[-1]
+        shutil.copyfile(self.good_mbox, self.mbox)
+        append_file(self.good_archive, self.mbox)
+        archivemail.archive(self.mbox)
+        self.verify()
+
+    def tearDown(self):
+        super(TestXIMAPMessage, self).tearDown()
+        archivemail.options.quiet = False
+
+
 ############# Test archiving maildirs ###############
 
 class TestArchiveMailboxdir(TestCaseInTempdir):