[HUDI-4109] Copy the old record directly when it is chosen for merging (#5603)

hudi-client/hudi-client-common/src/main/java/org/apache/hudi/io/HoodieMergeHandle.java

@@ -265,6 +265,9 @@ public class HoodieMergeHandle<T extends HoodieRecordPayload, I, K, O> extends H
       if (oldRecord != record) {
         // the incoming record is chosen
         isDelete = HoodieOperation.isDelete(hoodieRecord.getOperation());
+      } else {
+        // the incoming record is dropped
+        return false;
       }
     }
     return writeRecord(hoodieRecord, indexedRecord, isDelete);