Add necessary patchwork to work with 8-bit latin1 email

emailtunnel/__init__.py

@@ -22,6 +22,7 @@
 """
 
 import os
+import re
 import sys
 import logging
 import datetime
@@ -37,6 +38,11 @@
 import smtplib
 
 
+# From smtplib.py
+def _fix_eols(data):
+    return  re.sub(r'(?:\r\n|\n|\r(?!\n))', "\r\n", data)
+
+
 def now_string():
     """Return the current date and time as a string."""
     return datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S.%f")
@@ -61,6 +67,14 @@ def _sanity_check(self, message):
         a = message.rstrip('\n')
         b = str(self).rstrip('\n')
 
+        if '\ufffd' in a:
+            logging.debug(
+                'Original message is not sane; contains REPLACEMENT CHARACTER')
+
+        if '\ufffd' in b:
+            logging.debug(
+                'Parsed message is not sane; contains REPLACEMENT CHARACTER')
+
         if a == b:
             return
 
@@ -194,10 +208,19 @@ def collect_incoming_data(self, data):
         try:
             str_data = str(data, 'utf-8')
         except UnicodeDecodeError:
-            logging.error('ResilientSMTPChannel.collect_incoming_data: ' +
-                          'UnicodeDecodeError encountered; decoding with ' +
-                          'errors=replace')
-            str_data = data.decode('utf-8', 'replace')
+            try:
+                str_data = data.decode('latin1')
+            except UnicodeDecodeError:
+                logging.error(
+                    'ResilientSMTPChannel.collect_incoming_data: ' +
+                    'UnicodeDecodeError encountered; decoding as ' +
+                    'utf-8, errors=replace')
+                str_data = data.decode('utf-8', 'replace')
+            else:
+                logging.warning(
+                    'ResilientSMTPChannel.collect_incoming_data: ' +
+                    'UnicodeDecodeError encountered; decoding as ' +
+                    'latin1')
 
         # str_data.encode('utf-8').decode('utf-8') will surely not raise
         # a UnicodeDecodeError in SMTPChannel.collect_incoming_data.
@@ -295,7 +318,8 @@ def deliver(self, message, recipients, sender):
         logging.info('RCPT TO: %r MAIL FROM: %r Subject: %r'
                      % (recipients, sender, str(message.subject)))
         try:
-            relay_host.sendmail(sender, recipients, str(message))
+            str_message = _fix_eols(str(message))
+            relay_host.sendmail(sender, recipients, str_message.encode('latin1'))
         finally:
             try:
                 relay_host.quit()