Bug 202639 [Import/Export] [Import/Export] Improve warning messages in WizardFileSystemResourceExportPage1
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardFileSystemResourceExportPage1.java
boolean isValid = true;
        List resourcesToExport = getWhiteCheckedResources();
    	if (resourcesToExport.size() == 0){
    		setErrorMessage(DataTransferMessages.FileExport_noneSelected);
            isValid =  false;
    	} else {
			setErrorMessage(null);
		}
		return super.validateSourceGroup() && isValid;
	}
	/**
     * Get the message used to denote an empty destination.
     */
    protected String destinationEmptyMessage() {
        return DataTransferMessages.FileExport_destinationEmpty;
    }
    /**
     * Returns the name of a container with a location that encompasses targetDirectory.
     * Returns null if there is no conflict.
     * 
     * @param targetDirectory the path of the directory to check.
     * @return the conflicting container name or <code>null</code>
     */
    protected String getConflictingContainerNameFor(String targetDirectory) {
        IPath rootPath = ResourcesPlugin.getWorkspace().getRoot().getLocation();
        IPath testPath = new Path(targetDirectory);
        
        if(testPath.equals(rootPath))
        	return rootPath.lastSegment();