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/SourceContainerWorkbookPage.java
for (int i= cpelements.size() - 1; i >= 0 ; i--) {
			CPListElement cpe= (CPListElement)cpelements.get(i);
			if (isEntryKind(cpe.getEntryKind())) {
				
				
				if (!srcelements.remove(cpe)) {
					cpelements.remove(i);
					changeDone= true;
				} else if (lastSourceFolder == null) {
					lastSourceFolder= cpe;
				}
			}
		}
		if (!srcelements.isEmpty()) {
			int insertIndex= (lastSourceFolder == null) ? 0 : cpelements.indexOf(lastSourceFolder) + 1;
			cpelements.addAll(insertIndex, srcelements);
			changeDone= true;
		}
		if (changeDone) {
			fClassPathList.setElements(cpelements);
		}
	}
		
	private CPListElement openNewSourceContainerDialog(CPListElement existing) {	
		String title= (existing == null) ? NewWizardMessages.getString("SourceContainerWorkbookPage.NewSourceFolderDialog.new.title") : NewWizardMessages.getString("SourceContainerWorkbookPage.NewSourceFolderDialog.edit.title"); 
		IProject proj= fCurrJProject.getProject();
		NewSourceFolderDialog dialog= new NewSourceFolderDialog(getShell(), title, proj, getExistingContainers(existing), existing);
		dialog.setMessage(NewWizardMessages.getFormattedString("SourceContainerWorkbookPage.NewSourceFolderDialog.description", fProjPath.toString())); 
		if (dialog.open() == NewContainerDialog.OK) {
			IResource folder= dialog.getSourceFolder();