Bug 28510 java build path inconsistency [build path]
20021216 select rt.jar in the package explorer open properties it allows you to set the javadoc location but for source attachment you are sent somewhere else it's inconsistent - on the java build path they both look sort of the same (they sit under the same node in the tree)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/CPListElement.java
private IJavaProject fProject;
	
	private int fEntryKind;
	private IPath fPath;
	private IResource fResource;
	private boolean fIsExported;
	private boolean fIsMissing;
	
	private CPListElement fParentContainer;
		
	private IClasspathEntry fCachedEntry;
	private HashMap fAttributes;
	
	public CPListElement(IJavaProject project, int entryKind, IPath path, IResource res) {
		fProject= project;
		fEntryKind= entryKind;
		fPath= path;
		fAttributes= new HashMap();
		fResource= res;
		fIsExported= false;
		
		fIsMissing= false;
		fCachedEntry= null;
		fParentContainer= null;
		
		switch (entryKind) {
			case IClasspathEntry.CPE_SOURCE:
				createAttributeElement(OUTPUT, null);
				createAttributeElement(EXCLUSION, new Path[0]);