parse(mail|archive): handle early fail within email module

daxtens · stephenfin · commit c2cfced9c835 · 2017-07-03T20:42:00.000+01:00
Certain really messed up email messages can cause a failure within
the email module (at least on py3). Catch this.

Signed-off-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Stephen Finucane &lt;stephen@that.guru&gt;
diff --git a/patchwork/management/commands/parsearchive.py b/patchwork/management/commands/parsearchive.py
@@ -77,6 +77,23 @@ def handle(self, *args, **options):
 
         count = len(mbox)
 
+        # Iterate through the mbox. This will pick up exceptions that are only
+        # thrown when a broken email is found part way through. Without this
+        # block, we'd get the exception thrown in enumerate(mbox) below, which
+        # is harder to catch. This is due to a bug in the Python 'email'
+        # library, as described here:
+        #
+        #   https://lists.ozlabs.org/pipermail/patchwork/2017-July/004486.html
+        #
+        # The alternative is converting the mbox to a list of messages, but
+        # that requires holding the entire thing in memory, which is wateful.
+        try:
+            for m in mbox:
+                pass
+        except AttributeError:
+            logger.warning('Broken mbox/Maildir, aborting')
+            return
+
         logger.info('Parsing %d mails', count)
         for i, msg in enumerate(mbox):
             try:
diff --git a/patchwork/management/commands/parsemail.py b/patchwork/management/commands/parsemail.py
@@ -58,20 +58,25 @@ def add_arguments(self, parser):
     def handle(self, *args, **options):
         infile = args[0] if args else options['infile']
 
-        if infile:
-            logger.info('Parsing mail loaded by filename')
-            if six.PY3:
-                with open(infile, 'rb') as file_:
-                    mail = email.message_from_binary_file(file_)
-            else:
-                with open(infile) as file_:
-                    mail = email.message_from_file(file_)
-        else:
-            logger.info('Parsing mail loaded from stdin')
-            if six.PY3:
-                mail = email.message_from_binary_file(sys.stdin.buffer)
+        try:
+            if infile:
+                logger.info('Parsing mail loaded by filename')
+                if six.PY3:
+                    with open(infile, 'rb') as file_:
+                        mail = email.message_from_binary_file(file_)
+                else:
+                    with open(infile) as file_:
+                        mail = email.message_from_file(file_)
             else:
-                mail = email.message_from_file(sys.stdin)
+                logger.info('Parsing mail loaded from stdin')
+                if six.PY3:
+                    mail = email.message_from_binary_file(sys.stdin.buffer)
+                else:
+                    mail = email.message_from_file(sys.stdin)
+        except AttributeError:
+            logger.warning("Broken email ignored")
+            return
+
         try:
             result = parse_mail(mail, options['list_id'])
             if result:
