Fixing duplicate POP3 messages

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

@@ -1533,9 +1533,16 @@ class Core {
             Log.i(folder.name + " POP existing=" + ids.size());
 
             Map<String, TupleUidl> uidls = new HashMap<>();
+            Map<String, TupleUidl> msgids = new HashMap<>();
             for (TupleUidl id : ids)
                 if (id.uidl != null)
                     uidls.put(id.uidl, id);
+                else if (id.msgid != null)
+                    msgids.put(id.msgid, id);
+
+            for (TupleUidl id : uidls.values())
+                if (id.msgid != null && msgids.containsKey(id.msgid))
+                    db.message().deleteMessage(id.id);
 
             for (Message imessage : imessages)
                 try {

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

@@ -485,7 +485,7 @@ public interface DaoMessage {
             " AND NOT uid IS NULL")
     List<Long> getUids(long folder, Long received);
 
-    @Query("SELECT uidl, msgid FROM message" +
+    @Query("SELECT id, uidl, msgid FROM message" +
             " WHERE folder = :folder")
     List<TupleUidl> getUidls(long folder);
 

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

@@ -20,6 +20,7 @@ package eu.faircode.email;
 */
 
 public class TupleUidl {
+    long id;
     String uidl;
     String msgid;
 }