src/java.base/unix/classes/sun/nio/fs/UnixCopyFile.java

*** 1,7 ****
  /*
!  * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 371,380 ****
--- 371,396 ----
                  try { unlink(target); } catch (UnixException ignore) { }
              }
          }
      }
  
+     // throw a DirectoryNotEmpty exception if appropriate
+     static void ensureEmptyDir(UnixPath dir) throws IOException {
+         try {
+             long ptr = opendir(dir);
+             try (UnixDirectoryStream stream =
+                 new UnixDirectoryStream(dir, ptr, e -> true)) {
+                 if (stream.iterator().hasNext()) {
+                     throw new DirectoryNotEmptyException(
+                         dir.getPathForExceptionMessage());
+                 }
+             }
+         } catch (UnixException e) {
+             e.rethrowAsIOException(dir);
+         }
+     }
+ 
      // move file from source to target
      static void move(UnixPath source, UnixPath target, CopyOption... options)
          throws IOException
      {
          // permission check
*** 463,472 ****
--- 479,489 ----
              }
          }
  
          // copy source to target
          if (sourceAttrs.isDirectory()) {
+             ensureEmptyDir(source);
              copyDirectory(source, sourceAttrs, target, flags);
          } else {
              if (sourceAttrs.isSymbolicLink()) {
                  copyLink(source, sourceAttrs, target, flags);
              } else {