Store main part of the message outside of "parts" vector

src/mimefactory.rs

@@ -815,9 +815,10 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
         );
 
         // Message is sent as text/plain, with charset = utf-8
-        let mut parts = vec![PartBuilder::new()
+        let main_part = PartBuilder::new()
             .content_type(&mime::TEXT_PLAIN_UTF_8)
-            .body(message_text)];
+            .body(message_text);
+        let mut parts = Vec::new();
 
         // add attachment part
         if chat::msgtype_has_file(self.msg.viewtype) {
@@ -880,19 +881,19 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
             }
         }
 
+        if parts.is_empty() {
             // Single part, render as regular message.
-        if parts.len() == 1 {
+            Ok(main_part)
-            return Ok(parts.pop().unwrap());
+        } else {
-        }
-
             // Multiple parts, render as multipart.
             let mut message = PartBuilder::new().message_type(MimeMultipartType::Mixed);
+            message = message.child(main_part.build());
             for part in parts.into_iter() {
                 message = message.child(part.build());
             }
-
             Ok(message)
         }
+    }
 
     /// Render an MDN
     fn render_mdn(&mut self) -> Result<PartBuilder, Error> {