Program: 47498
Project: 47498
Buggy source:
public void fetchRepositoryFileTree(final AsyncCallback<RepositoryFileTree> callback,Integer depth,String filter,Boolean showHidden){
  beforeFetchRepositoryFileTree();
  RequestBuilder builder=null;
  String url=GWT.getHostPageBaseURL() + "String_Node_Str";
  if (depth == null) {
    depth=-1;
  }
  if (filter == null) {
    filter="String_Node_Str";
  }
  if (showHidden == null) {
    showHidden=Boolean.FALSE;
  }
  url=url + "String_Node_Str" + depth+ "String_Node_Str"+ filter+ "String_Node_Str"+ showHidden+ "String_Node_Str"+ System.currentTimeMillis();
  builder=new RequestBuilder(RequestBuilder.GET,url);
  builder.setHeader("String_Node_Str","String_Node_Str");
  RequestCallback innerCallback=new RequestCallback(){
    public void onError(    Request request,    Throwable exception){
      Window.alert(exception.toString());
    }
    public void onResponseReceived(    Request request,    Response response){
      if (response.getStatusCode() == Response.SC_OK) {
        String json=response.getText();
        System.out.println(json);
        final JsonToRepositoryFileTreeConverter converter=new JsonToRepositoryFileTreeConverter(response.getText());
        fileTree=converter.getTree();
        String deletedFilesUrl=GWT.getHostPageBaseURL() + "String_Node_Str" + System.currentTimeMillis();
        ;
        RequestBuilder deletedFilesRequestBuilder=new RequestBuilder(RequestBuilder.GET,deletedFilesUrl);
        deletedFilesRequestBuilder.setHeader("String_Node_Str","String_Node_Str");
        try {
          deletedFilesRequestBuilder.sendRequest(null,new RequestCallback(){
            public void onError(            Request request,            Throwable exception){
              fireRepositoryFileTreeFetched();
              Window.alert(exception.toString());
            }
            public void onResponseReceived(            Request delRequest,            Response delResponse){
              if (delResponse.getStatusCode() == Response.SC_OK) {
                trashItems=JsonToRepositoryFileTreeConverter.getTrashFiles(delResponse.getText());
                fireRepositoryFileTreeFetched();
              }
 else {
                fireRepositoryFileTreeFetched();
              }
            }
          }
);
        }
 catch (        Exception e) {
          fireRepositoryFileTreeFetched();
        }
        if (callback != null) {
          callback.onSuccess(fileTree);
        }
      }
 else {
        fileTree=new RepositoryFileTree();
        RepositoryFile errorFile=new RepositoryFile();
        errorFile.setFolder(true);
        errorFile.setName("String_Node_Str");
        fileTree.setFile(errorFile);
      }
    }
  }
;
  try {
    builder.sendRequest(null,innerCallback);
  }
 catch (  RequestException e) {
    e.printStackTrace();
  }
}

Fixed version (ground truth):
public void fetchRepositoryFileTree(final AsyncCallback<RepositoryFileTree> callback,Integer depth,String filter,Boolean showHidden){
  beforeFetchRepositoryFileTree();
  RequestBuilder builder=null;
  String url=GWT.getHostPageBaseURL() + "String_Node_Str";
  if (depth == null) {
    depth=-1;
  }
  if (filter == null) {
    filter="String_Node_Str";
  }
  if (showHidden == null) {
    showHidden=Boolean.FALSE;
  }
  url=url + "String_Node_Str" + depth+ "String_Node_Str"+ filter+ "String_Node_Str"+ showHidden+ "String_Node_Str"+ System.currentTimeMillis();
  builder=new RequestBuilder(RequestBuilder.GET,url);
  builder.setHeader("String_Node_Str","String_Node_Str");
  RequestCallback innerCallback=new RequestCallback(){
    public void onError(    Request request,    Throwable exception){
      Window.alert(exception.toString());
    }
    public void onResponseReceived(    Request request,    Response response){
      if (response.getStatusCode() == Response.SC_OK) {
        String json=response.getText();
        System.out.println(json);
        final JsonToRepositoryFileTreeConverter converter=new JsonToRepositoryFileTreeConverter(response.getText());
        fileTree=converter.getTree();
        String deletedFilesUrl=GWT.getHostPageBaseURL() + "String_Node_Str" + System.currentTimeMillis();
        ;
        RequestBuilder deletedFilesRequestBuilder=new RequestBuilder(RequestBuilder.GET,deletedFilesUrl);
        deletedFilesRequestBuilder.setHeader("String_Node_Str","String_Node_Str");
        try {
          deletedFilesRequestBuilder.sendRequest(null,new RequestCallback(){
            public void onError(            Request request,            Throwable exception){
              fireRepositoryFileTreeFetched();
              Window.alert(exception.toString());
            }
            public void onResponseReceived(            Request delRequest,            Response delResponse){
              if (delResponse.getStatusCode() == Response.SC_OK) {
                try {
                  trashItems=JsonToRepositoryFileTreeConverter.getTrashFiles(delResponse.getText());
                }
 catch (                Throwable t) {
                }
                fireRepositoryFileTreeFetched();
              }
 else {
                fireRepositoryFileTreeFetched();
              }
            }
          }
);
        }
 catch (        Exception e) {
          fireRepositoryFileTreeFetched();
        }
        if (callback != null) {
          callback.onSuccess(fileTree);
        }
      }
 else {
        fileTree=new RepositoryFileTree();
        RepositoryFile errorFile=new RepositoryFile();
        errorFile.setFolder(true);
        errorFile.setName("String_Node_Str");
        fileTree.setFile(errorFile);
      }
    }
  }
;
  try {
    builder.sendRequest(null,innerCallback);
  }
 catch (  RequestException e) {
    e.printStackTrace();
  }
}