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/LibrariesWorkbookPage.java
CPListElement curr= libentries[i];
				if (!cplist.contains(curr) && !elementsToAdd.contains(curr)) {
					elementsToAdd.add(curr);
					addAttachmentsFromExistingLibs(curr);
				}
			}
			fLibrariesList.addElements(elementsToAdd);
			fLibrariesList.postSetSelection(new StructuredSelection(libentries));
		}
	}
	
	protected void libaryPageDoubleClicked(TreeListDialogField field) {
		List selection= fLibrariesList.getSelectedElements();
		if (canEdit(selection)) {
			editEntry();
		}
	}
	/**
	 * Method editEntry.
	 */
	private void editEntry() {
		List selElements= fLibrariesList.getSelectedElements();
		if (selElements.size() != 1) {
			return;
		}
		Object elem= selElements.get(0);
		if (fLibrariesList.getIndexOfElement(elem) != -1) {
			editElementEntry((CPListElement) elem);
		} else if (elem instanceof CPListElementAttribute) {
			editAttributeEntry((CPListElementAttribute) elem);