Refactoring

app/src/main/java/eu/faircode/email/Core.java

@@ -708,17 +708,10 @@ class Core {
         ((GmailMessage) imessage).setLabels(new String[]{label}, set);
 
         // Gmail does not push label changes
-
-        List<String> labels = new ArrayList<>();
-        if (message.labels != null)
-            labels.addAll(Arrays.asList(message.labels));
-        labels.remove(label);
-        if (set)
-            labels.add(label);
+        message.setLabel(label, set);
 
         DB db = DB.getInstance(context);
-        db.message().setMessageLabels(message.id,
-                DB.Converters.fromStringArray(labels.toArray(new String[0])));
+        db.message().setMessageLabels(message.id, DB.Converters.fromStringArray(message.labels));
     }
 
     private static void onAdd(Context context, JSONArray jargs, EntityFolder folder, EntityMessage message, IMAPStore istore, IMAPFolder ifolder, State state) throws MessagingException, IOException {

app/src/main/java/eu/faircode/email/EntityMessage.java

@@ -244,6 +244,16 @@ public class EntityMessage implements Serializable {
         return "notification." + sender.getAddress().toLowerCase(Locale.ROOT);
     }
 
+    void setLabel(String label, boolean set) {
+        List<String> list = new ArrayList<>();
+        if (labels != null)
+            list.addAll(Arrays.asList(labels));
+        list.remove(label);
+        if (set)
+            list.add(label);
+        labels = list.toArray(new String[0]);
+    }
+
     static File getFile(Context context, Long id) {
         File dir = new File(context.getFilesDir(), "messages");
         if (!dir.exists())