Bug 310494 [LinkedResources] Preference "Link and create virtual folders" does not work
I20100425-2000 The 2 options on the Linked Resourced with name "Link and create virtual folders" don't work. When they are selected, dropping items does nothing. In CopyFilesAndFoldersOperation#copyOrLinkFiles(..), the test "hasFlag(dropOperation, ImportTypeDialog.IMPORT_VIRTUAL_FOLDERS_AND_LINKS)" always fails because dropOperation is always COPY.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/CopyFilesAndFoldersOperation.java
* Eclipse compiler with regards to visibility and type resolution when
	 * linking.
	 * </p>
	 * 
	 * @param destination
	 *            the destination container
	 * @param sourceStores
	 *            the source IFileStore
	 * @return an error message, or <code>null</code> if the path is valid
	 */
	private String validateImportDestinationInternal(IContainer destination,
			IFileStore[] sourceStores) {
		if (!isAccessible(destination))
			return IDEWorkbenchMessages.CopyFilesAndFoldersOperation_destinationAccessError;
		if (!destination.isVirtual()) {
		IFileStore destinationStore;
		try {
			destinationStore = EFS.getStore(destination.getLocationURI());
		} catch (CoreException exception) {
			IDEWorkbenchPlugin.log(exception.getLocalizedMessage(), exception);
			return NLS
					.bind(
							IDEWorkbenchMessages.CopyFilesAndFoldersOperation_internalError,
							exception.getLocalizedMessage());
		}
		for (int i = 0; i < sourceStores.length; i++) {
			IFileStore sourceStore = sourceStores[i];
			IFileStore sourceParentStore = sourceStore.getParent();
			if (sourceStore != null) {
				if (destinationStore.equals(sourceStore)