Bug 131000 [EFS] Drag and Drop of Folder with Spaces produces two folders in Navigator View (and other views that deal with resources)
If you grab a folder on the file system that has spaces in the name and drag it into a project in the navigator view, the folder is copied twice, once with escaped spaces (%20) and once without any escaped spaces. The folder with escaped spaces is the one with the content, the other folder has no content. This is a fairly serious bug for us because we use the CopyFilesAndFoldersOperation to do our own manipulation like this and the bug is in that class.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/wizards/datatransfer/FileStoreStructureProvider.java
/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.wizards.datatransfer;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileStore;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
/**
 * FileStoreStructureProvider is the structure provider for {@link IFileStore}
 * based file structures.
 * 
 * @since 3.2
 * 
 */
public class FileStoreStructureProvider implements IImportStructureProvider {