From 36bbff20793322f8a6035a4ba6847c787a589643 Mon Sep 17 00:00:00 2001
From: Patrick Ulbrich <zulu99@gmx.net>
Date: Sat, 17 Sep 2016 12:54:47 +0200
Subject: [PATCH] Properly close connection if it has been reset by remote peer

---
 Mailnag/backends/imap.py | 18 +++++++++---------
 Mailnag/daemon/idlers.py |  2 --
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/Mailnag/backends/imap.py b/Mailnag/backends/imap.py
index 74dc0c8..30dd15d 100644
--- a/Mailnag/backends/imap.py
+++ b/Mailnag/backends/imap.py
@@ -49,7 +49,6 @@ class IMAPMailboxBackend(MailboxBackend):
 		self.ssl = ssl # bool
 		self.folders = folders
 		self._conn = None
-		self._conn_closed = True
 
 
 	def open(self):
@@ -89,8 +88,6 @@ class IMAPMailboxBackend(MailboxBackend):
 			except:	pass
 			raise # re-throw exception
 		
-		self._conn_closed = False
-		
 		# notify_next_change() (IMAP IDLE) requires a selected folder
 		if self._conn.state == AUTH:
 			self._select()
@@ -99,9 +96,7 @@ class IMAPMailboxBackend(MailboxBackend):
 	def close(self):
 		# if conn has already been closed, don't try to close it again
 		if self._conn != None:
-			if not self._conn_closed:
-				self._conn.close()
-				self._conn_closed = True
+			self._conn.close()
 			self._conn.logout()
 			self._conn = None
 
@@ -109,8 +104,7 @@ class IMAPMailboxBackend(MailboxBackend):
 	def is_open(self):
 		return (self._conn != None) and \
 				(self._conn.state != imaplib.LOGOUT) and \
-				(not self._conn.Terminate) and \
-				(not self._conn_closed)
+				(not self._conn.Terminate)
 
 
 	def list_messages(self):
@@ -185,7 +179,13 @@ class IMAPMailboxBackend(MailboxBackend):
 		# idle callback (runs on a further thread)
 		def _idle_callback(args):
 			# check if the connection has been reset by provider
-			self._conn_closed = (args[2] != None) and (args[2][0] is self._conn.abort)
+			if (args[2] != None) and (args[2][0] is self._conn.abort):
+				# conn has already been closed, don't try to close it again
+				# self._conn.close() # (calls idle_callback)
+				
+				# shutdown existing callback thread
+				self._conn.logout()
+				self._conn = None
 			
 			# call actual callback
 			callback(args)
diff --git a/Mailnag/daemon/idlers.py b/Mailnag/daemon/idlers.py
index df4eb38..8bbb413 100644
--- a/Mailnag/daemon/idlers.py
+++ b/Mailnag/daemon/idlers.py
@@ -104,8 +104,6 @@ class Idler(object):
 	def _reconnect(self):
 		# connection has been reset by provider -> try to reconnect
 		logging.info("Idler thread for account '%s' has been disconnected" % self._account.name)
-		
-		self._account.close()
 
 		while (not self._account.is_open()) and (not self._event.isSet()):
 			logging.info("Trying to reconnect Idler thread for account '%s'." % self._account.name)