1 files changed, 23 insertions, 17 deletions
diff --git a/java/src/main/java/com/google/protobuf/nano/ExtendableMessageNano.java b/java/src/main/java/com/google/protobuf/nano/ExtendableMessageNano.java
index 4fe8dce..5984d35 100644
--- a/java/src/main/java/com/google/protobuf/nano/ExtendableMessageNano.java
+++ b/java/src/main/java/com/google/protobuf/nano/ExtendableMessageNano.java
@@ -68,18 +68,6 @@ public abstract class ExtendableMessageNano<M extends ExtendableMessageNano<M>>
     }
 
     /**
-     * Checks if there is a value stored for the specified extension in this
-     * message.
-     */
-    public final boolean hasExtension(Extension<M, ?> extension) {
-        if (unknownFieldData == null) {
-            return false;
-        }
-        FieldData field = unknownFieldData.get(WireFormatNano.getTagFieldNumber(extension.tag));
-        return field != null;
-    }
-
-    /**
      * Gets the value stored in the specified extension of this message.
      */
     public final <T> T getExtension(Extension<M, T> extension) {
@@ -160,10 +148,28 @@ public abstract class ExtendableMessageNano<M extends ExtendableMessageNano<M>>
         return true;
     }
 
-    @Override
-    public M clone() throws CloneNotSupportedException {
-        M cloned = (M) super.clone();
-        InternalNano.cloneUnknownFieldData(this, cloned);
-        return cloned;
+    /**
+     * Returns whether the stored unknown field data in this message is equivalent to that in the
+     * other message.
+     *
+     * @param other the other message.
+     * @return whether the two sets of unknown field data are equal.
+     */
+    protected final boolean unknownFieldDataEquals(M other) {
+        if (unknownFieldData == null || unknownFieldData.isEmpty()) {
+            return other.unknownFieldData == null || other.unknownFieldData.isEmpty();
+        } else {
+            return unknownFieldData.equals(other.unknownFieldData);
+        }
+    }
+
+    /**
+     * Computes the hashcode representing the unknown field data stored in this message.
+     *
+     * @return the hashcode for the unknown field data.
+     */
+    protected final int unknownFieldDataHashCode() {
+        return (unknownFieldData == null || unknownFieldData.isEmpty()
+                ? 0 : unknownFieldData.hashCode());
     }
 }