2 files changed, 27 insertions, 0 deletions

diff --git a/src/mailman/core/switchboard.py b/src/mailman/core/switchboard.py
index 315d564f3..e9e5e95f1 100644
--- a/src/mailman/core/switchboard.py
+++ b/src/mailman/core/switchboard.py
@@ -167,6 +167,13 @@ class Switchboard:
     def finish(self, filebase, preserve=False):
         """See `ISwitchboard`."""
         bakfile = os.path.join(self.queue_directory, filebase + '.bak')
+        # It is possible for a queue entry to be created by a non-Mailman user
+        # and not be readable by the Mailman user:group.  If this happens, we
+        # get here and the file is a .pck rather than a .bak.
+        pckfile = os.path.join(self.queue_directory, filebase + '.pck')
+        if not os.path.isfile(bakfile) and os.path.isfile(pckfile):
+            # We have a .pck and not a .bak so switch the name for the next.
+            bakfile = pckfile
         try:
             if preserve:
                 bad_dir = config.switchboards['bad'].queue_directory
diff --git a/src/mailman/core/tests/test_switchboard.py b/src/mailman/core/tests/test_switchboard.py
index 5303abb9b..7fe527ee1 100644
--- a/src/mailman/core/tests/test_switchboard.py
+++ b/src/mailman/core/tests/test_switchboard.py
@@ -17,6 +17,7 @@
 
 """Switchboard tests."""
 
+import os
 import unittest
 
 from mailman.config import config
@@ -51,3 +52,22 @@ Message-ID: <ant>
         traceback = error_log.read().splitlines()
         self.assertEqual(traceback[1], 'Traceback (most recent call last):')
         self.assertEqual(traceback[-1], 'OSError: Oops!')
+
+    def test_no_bak_but_pck(self):
+        # if there is no .bak file but a .pck with the same filebase,
+        # .finish() should handle the .pck.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Message-ID: <ant>
+
+""")
+        switchboard = config.switchboards['shunt']
+        # Enqueue the message.
+        filebase = switchboard.enqueue(msg)
+        # Now call .finish() without first dequeueing.
+        switchboard.finish(filebase, preserve=True)
+        # And ensure the file got preserved.
+        bad_dir = config.switchboards['bad'].queue_directory
+        psvfile = os.path.join(bad_dir, filebase + '.psv')
+        self.assertTrue(os.path.isfile(psvfile))