@@ -38,6 +38,6 @@ class BaseEncryptionKeyMetadata implements EncryptionKeyMetadata {
   @Override
   public EncryptionKeyMetadata copy() {
     return new BaseEncryptionKeyMetadata(
-        ByteBuffers.copy(keyMetadata));
+        keyMetadata == null ? null : ByteBuffers.copy(keyMetadata));
   }
 }
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.netflix.iceberg.encryption;

import com.netflix.iceberg.util.ByteBuffers;

import java.nio.ByteBuffer;

class BaseEncryptionKeyMetadata implements EncryptionKeyMetadata {
  private final ByteBuffer keyMetadata;

  BaseEncryptionKeyMetadata(ByteBuffer keyMetadata) {
    this.keyMetadata = keyMetadata;
  }

  @Override
  public ByteBuffer keyMetadata() {
    return keyMetadata;
  }

  @Override
  public EncryptionKeyMetadata copy() {
    return new BaseEncryptionKeyMetadata(
        ByteBuffers.copy(keyMetadata));
  }
}

What about making `ByteBuffers.copy` null-safe? That would prevent future problems like this.