Bug 161828 [Undo] - second undo on folder move/copy merge restores old snapshot
Project A folder file1 file2 file3 file4 subfolder file1 file2 file3 file4 Move the "folder" to this existing project: Project B folder file1 file2 file3 file4 file5 file6 subfolder file1 file2 file3 file4 The move operation correctly replaces the content of file1, file2, file3, file4 in the ProjectB folder and the content of file1, file2, file3, file4 in the subfolder. Undo the move. The files return to their original location in ProjectA, and the content of the files in ProjectB have reverted to their content before the move. Redo the move. Everything still fine. Undo the move. Now the files have returned to their original location in ProjectA, but the content of the files in ProjectB still have the content from the ProjectA files.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/undo/ResourceDescription.java
/**
	 * Given a resource handle, create an actual resource with the attributes of
	 * the receiver resource description.
	 * 
	 * @param resource
	 *            the resource handle
	 * @param monitor
	 *            the progress monitor to be used when creating the resource
	 * @throws CoreException
	 */
	public abstract void createExistentResourceFromHandle(IResource resource,
			IProgressMonitor monitor) throws CoreException;
	/**
	 * Return a boolean indicating whether this resource description has enough
	 * information to create a resource.
	 * 
	 * @return <code>true</code> if the resource can be created, and
	 *         <code>false</code> if it does not have enough information
	 */
	public boolean isValid() {
		return parent == null || parent.exists();
	}
	/**
	 * Record the last known history of this resource if available.
	 * 
	 * @param resource
	 *            the resource whose history is to be recorded.
	 * @param monitor
	 *            the progress monitor to be used
	 * @throws CoreException