Bug 65243 Build path dialog: Disable 'Add folder' when ex-/inclusion selected
RC1 On the build path dialog it would be better to disable 'Add folder' when ex-/inclusion selected to avoid confusion to what 'Add folder is releated'
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/LibrariesWorkbookPage.java
return new CPListElement[] { new CPListElement(fCurrJProject, IClasspathEntry.CPE_LIBRARY, configured, null) };
			}
		}		
		return null;
	}
		
	private CPListElement[] openVariableSelectionDialog(CPListElement existing) {
		List existingElements= fLibrariesList.getElements();
		ArrayList existingPaths= new ArrayList(existingElements.size());
		for (int i= 0; i < existingElements.size(); i++) {
			CPListElement elem= (CPListElement) existingElements.get(i);
			if (elem.getEntryKind() == IClasspathEntry.CPE_VARIABLE) {
				existingPaths.add(elem.getPath());
			}
		}
		IPath[] existingPathsArray= (IPath[]) existingPaths.toArray(new IPath[existingPaths.size()]);
		
		if (existing == null) {
			IPath[] paths= BuildPathDialogAccess.chooseVariableEntries(getShell(), existingPathsArray);
			if (paths != null) {
				ArrayList result= new ArrayList();
				for (int i = 0; i < paths.length; i++) {
					CPListElement elem= new CPListElement(fCurrJProject, IClasspathEntry.CPE_VARIABLE, paths[i], null);
					IPath resolvedPath= JavaCore.getResolvedVariablePath(paths[i]);
					elem.setIsMissing((resolvedPath == null) || !resolvedPath.toFile().exists());
					if (!existingElements.contains(elem)) {
						result.add(elem);
					}
				}
				return (CPListElement[]) result.toArray(new CPListElement[result.size()]);