Prevent NoMethodError on Mail#bounced? for emails without multipart o…

…r delivery_status_part

lib/mail/message.rb

@@ -1300,31 +1300,31 @@ def delivery_status_part
     end
 
     def bounced?
-      delivery_status_part.bounced?
+      delivery_status_part and delivery_status_part.bounced?
     end
 
     def action
-      delivery_status_part.action
+      delivery_status_part and delivery_status_part.action
     end
 
     def final_recipient
-      delivery_status_part.final_recipient
+      delivery_status_part and delivery_status_part.final_recipient
     end
 
     def error_status
-      delivery_status_part.error_status
+      delivery_status_part and delivery_status_part.error_status
     end
 
     def diagnostic_code
-      delivery_status_part.diagnostic_code
+      delivery_status_part and delivery_status_part.diagnostic_code
     end
 
     def remote_mta
-      delivery_status_part.remote_mta
+      delivery_status_part and delivery_status_part.remote_mta
     end
 
     def retryable?
-      delivery_status_part.retryable?
+      delivery_status_part and delivery_status_part.retryable?
     end
 
     # Returns the current boundary for this message part

spec/mail/message_spec.rb

@@ -31,7 +31,11 @@ def basic_email
       mail.header.class.should == Mail::Header
       mail.body.class.should == Mail::Body
     end
-
+
+    it "should not report basic emails as bounced" do
+      Mail::Message.new.should_not be_bounced
+    end
+
     it "should be able to parse a basic email" do
       doing { Mail::Message.new(File.read(fixture('emails', 'plain_emails', 'basic_email.eml'))) }.should_not raise_error
     end