Subject prefixes fixes

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

@@ -722,7 +722,7 @@ public class EntityRule {
 
         String subject = (message.subject == null ? "" : message.subject);
         if (prefix_once)
-            EntityMessage.collapsePrefixes(context, message.language, subject, !TextUtils.isEmpty(to));
+            subject = EntityMessage.collapsePrefixes(context, message.language, subject, !TextUtils.isEmpty(to));
 
         reply.subject = context.getString(
                 TextUtils.isEmpty(to)

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

@@ -304,6 +304,7 @@ public class ServiceUI extends IntentService {
     private void onReplyDirect(long id, Intent intent) throws IOException {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
         boolean prefix_once = prefs.getBoolean("prefix_once", true);
+        boolean alt_re = prefs.getBoolean("alt_re", false);
         boolean plain_only = prefs.getBoolean("plain_only", false);
 
         DB db = DB.getInstance(this);
@@ -345,7 +346,7 @@ public class ServiceUI extends IntentService {
             reply.thread = ref.thread;
             reply.to = ref.from;
             reply.from = new Address[]{new InternetAddress(identity.email, identity.name, StandardCharsets.UTF_8.name())};
-            reply.subject = getString(R.string.title_subject_reply, subject);
+            reply.subject = getString(alt_re ? R.string.title_subject_reply_alt : R.string.title_subject_reply, subject);
             reply.received = new Date().getTime();
             reply.seen = true;
             reply.ui_seen = true;