Work around a line-length limit in poplib

Work around a limitation in python2.7 implementation of poplib (for the
pop3 protocol for fetching emails): It seems poplib applies a
line-length limit not just to the lines involving the pop3 protocol but
to any email content, too. This sometimes leads to tracebacks whenever
an email exceeding this limit is encountered. We "fix" this by
monkey-patching poplib with a larger line-limit. Thanks to Heiko
Stegmann for discovering this.

Author: schlatterbeck

CHANGES.txt

@@ -505,6 +505,13 @@ Fixed:
   normal database operation.
 - Allow empty content property for file and message via xmlrpc
   interface. This used to raise a traceback in the (sql) backend.
+- Work around a limitation in python2.7 implementation of poplib (for
+  the pop3 protocol for fetching emails): It seems poplib applies a
+  line-length limit not just to the lines involving the pop3 protocol
+  but to any email content, too. This sometimes leads to tracebacks
+  whenever an email exceeding this limit is encountered. We "fix" this
+  by monkey-patching poplib with a larger line-limit. Thanks to Heiko
+  Stegmann for discovering this.
 
 
 2016-01-11: 1.5.1

roundup/mailgw.py

@@ -1452,6 +1452,15 @@ def _do_pop(self, server, user, password, apop, ssl):
         '''Read a series of messages from the specified POP server.
         '''
         import getpass, poplib, socket
+        # Monkey-patch poplib to have a large line-limit
+        # Seems that in python2.7 poplib applies a line-length limit not
+        # just to the lines that take care of the pop3 protocol but also
+        # to all email content
+        # See, e.g.,
+        # https://readlist.com/lists/python.org/python-list/69/346982.html
+        # https://stackoverflow.com/questions/30976106/python-poplib-error-proto-line-too-+long?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa
+        if 0 < getattr (poplib, '_MAXLINE', -1) < 100*1024:
+            poplib._MAXLINE = 100*1024
         try:
             if not user:
                 user = raw_input('User: ')