Fix pop3 SSL state leaking over multisite

app/jobs/scheduled/poll_mailbox.rb

@@ -73,10 +73,10 @@ module Jobs
     end
 
     def poll_pop3
-      Net::POP3.start(SiteSetting.pop3_polling_host,
-                      SiteSetting.pop3_polling_port,
-                      SiteSetting.pop3_polling_username,
-                      SiteSetting.pop3_polling_password) do |pop|
+      connection = Net::POP3.new(SiteSetting.pop3_polling_host, SiteSetting.pop3_polling_port)
+      connection.enable_ssl if SiteSetting.pop3_polling_ssl
+
+      connection.start(SiteSetting.pop3_polling_username, SiteSetting.pop3_polling_password) do |pop|
         unless pop.mails.empty?
           pop.each do |mail|
             handle_mail(mail)

config/site_settings.yml

@@ -386,6 +386,7 @@ email:
   reply_by_email_enabled: false
   reply_by_email_address: ''
   pop3_polling_enabled: false
+  pop3_polling_ssl: true
   pop3_polling_period_mins: 5
   pop3_polling_host: ''
   pop3_polling_port: 995

spec/jobs/poll_mailbox_spec.rb

@@ -32,13 +32,28 @@ describe Jobs::PollMailbox do
       error = Net::POPAuthenticationError.new
       data = { limit_once_per: 1.hour, message_params: { error: error }}
 
-      Net::POP3.expects(:start).raises(error)
+      Net::POP3.any_instance.expects(:start).raises(error)
 
       Discourse.expects(:handle_exception)
 
       poller.poll_pop3
     end
 
+    it "calls enable_ssl when the setting is enabled" do
+      SiteSetting.pop3_polling_ssl = true
+      Net::POP3.any_instance.stubs(:start)
+      Net::POP3.any_instance.expects(:enable_ssl)
+
+      poller.poll_pop3
+    end
+
+    it "does not call enable_ssl when the setting is off" do
+      SiteSetting.pop3_polling_ssl = false
+      Net::POP3.any_instance.stubs(:start)
+      Net::POP3.any_instance.expects(:enable_ssl).never
+
+      poller.poll_pop3
+    end
   end
 
   # Testing mock for the email objects that you get