Program: 31367
Project: 31367
Buggy source:
private static void extractSite(String dir) throws URISyntaxException, IOException {
  URL url=HttpServer.class.getResource("String_Node_Str");
  final Path source=Paths.get(url.toURI());
  final Path target=Paths.get(dir);
  final EnumSet<FileVisitOption> walkOptions=EnumSet.of(FileVisitOption.FOLLOW_LINKS);
  final CopyOption[] copyOptions=new CopyOption[]{COPY_ATTRIBUTES,REPLACE_EXISTING};
  Files.walkFileTree(source,walkOptions,Integer.MAX_VALUE,new FileVisitor<Path>(){
    private boolean skip=true;
    @Override public FileVisitResult preVisitDirectory(    Path dir,    BasicFileAttributes attrs){
      if (skip) {
        skip=false;
      }
 else {
        Path newDirectory=target.resolve(source.relativize(dir));
        try {
          Files.copy(dir,newDirectory,copyOptions);
        }
 catch (        FileAlreadyExistsException ignore) {
        }
catch (        IOException x) {
          return FileVisitResult.SKIP_SUBTREE;
        }
      }
      return FileVisitResult.CONTINUE;
    }
    @Override public FileVisitResult visitFile(    Path file,    BasicFileAttributes attrs) throws IOException {
      Files.copy(file,target.resolve(source.relativize(file)),copyOptions);
      return FileVisitResult.CONTINUE;
    }
    @Override public FileVisitResult visitFileFailed(    Path file,    IOException exc){
      return FileVisitResult.CONTINUE;
    }
    @Override public FileVisitResult postVisitDirectory(    Path dir,    IOException exc){
      return FileVisitResult.CONTINUE;
    }
  }
);
}

Fixed version (ground truth):
private static void extractSite(String dir,boolean force) throws URISyntaxException, IOException {
  URL url=HttpServer.class.getResource("String_Node_Str");
  final Path source=Paths.get(url.toURI());
  final Path target=Paths.get(dir);
  final EnumSet<FileVisitOption> walkOptions=EnumSet.of(FileVisitOption.FOLLOW_LINKS);
  final CopyOption[] copyOptions=new CopyOption[]{COPY_ATTRIBUTES,REPLACE_EXISTING};
  if (force) {
    File pub=new File(dir,"String_Node_Str");
    if (pub.exists()) {
      com.questdb.misc.Files.delete(pub);
    }
  }
  Files.walkFileTree(source,walkOptions,Integer.MAX_VALUE,new FileVisitor<Path>(){
    private boolean skip=true;
    @Override public FileVisitResult preVisitDirectory(    Path dir,    BasicFileAttributes attrs){
      if (skip) {
        skip=false;
      }
 else {
        Path newDirectory=target.resolve(source.relativize(dir));
        try {
          Files.copy(dir,newDirectory,copyOptions);
        }
 catch (        FileAlreadyExistsException ignore) {
        }
catch (        IOException x) {
          return FileVisitResult.SKIP_SUBTREE;
        }
      }
      return FileVisitResult.CONTINUE;
    }
    @Override public FileVisitResult visitFile(    Path file,    BasicFileAttributes attrs) throws IOException {
      Files.copy(file,target.resolve(source.relativize(file)),copyOptions);
      return FileVisitResult.CONTINUE;
    }
    @Override public FileVisitResult visitFileFailed(    Path file,    IOException exc){
      return FileVisitResult.CONTINUE;
    }
    @Override public FileVisitResult postVisitDirectory(    Path dir,    IOException exc){
      return FileVisitResult.CONTINUE;
    }
  }
);
}