Bug 8808 Class folder: Must use create to add an existing folder
Build I20020129 "Add Folders..." does not show the project itself. I have to do the following trick to add an existing folder as class folder: Press "Create folder" Enter the name of the existing folder (hopfully it's in the project root :-) Voila BTW: I can't do this a second time - the UI tells me it already exists - which is OK. To be consistent with other dialogs "Create Folder" should always warn about existing projects.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/LibrariesWorkbookPage.java
case 2: 
			libentries= chooseJarFiles();
			break;
		case 3: 
			libentries= chooseExtJarFiles();
			break;
		case 4: 
			libentries= chooseVariableEntries();
			break;				
		case 6: 
			List selElements= fLibrariesList.getSelectedElements();
			CPListElement selElement= (CPListElement) selElements.get(0);				
			SourceAttachmentDialog dialog= new SourceAttachmentDialog(getShell(), selElement.getClasspathEntry());
			if (dialog.open() == dialog.OK) {
				selElement.setSourceAttachment(dialog.getSourceAttachmentPath(), dialog.getSourceAttachmentRootPath());
				selElement.setJavadocLocation(dialog.getJavadocLocation());
				fLibrariesList.refresh();
				fClassPathList.refresh();
			}
			break;
		}
		if (libentries != null) {
			int nElementsChosen= libentries.length;					
			
			List cplist= fLibrariesList.getElements();
			List elementsToAdd= new ArrayList(nElementsChosen);
			
			for (int i= 0; i < nElementsChosen; i++) {
				CPListElement curr= libentries[i];
				if (!cplist.contains(curr) && !elementsToAdd.contains(curr)) {