Bug 73984 Editing user library jar path after path change does not work [build path]
1) Create a directory containing jar file 2) Add this jar file to a new user library 3) Rename directory from 1) 4) Update the path to jar file in user libraries (select old jar reference, select new location in browser, open -> path is not updated, but old path is still used
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/UserLibraryPreferencePage.java
private IStatus validateSettings() {
			String name= fNameField.getText();
			if (name.length() == 0) {
				return new StatusInfo(IStatus.ERROR, PreferencesMessages.getString("UserLibraryPreferencePage.LibraryNameDialog.name.error.entername")); 
			}
			for (int i= 0; i < fExistingLibraries.size(); i++) {
				CPUserLibraryElement curr= (CPUserLibraryElement) fExistingLibraries.get(i);
				if (curr != fElementToEdit && name.equals(curr.getName())) {
					return new StatusInfo(IStatus.ERROR, PreferencesMessages.getFormattedString("UserLibraryPreferencePage.LibraryNameDialog.name.error.exists", name)); 
				}
			}
			IStatus status= ResourcesPlugin.getWorkspace().validateName(name, IResource.FILE);
			if (status.matches(IStatus.ERROR)) {
				return new StatusInfo(IStatus.ERROR, "Name contains invalid characters."); 
			}
			return StatusInfo.OK_STATUS;
		}
		
		public CPUserLibraryElement getNewLibrary() {
			CPListElement[] entries= null;
			if (fElementToEdit != null) {
				entries= fElementToEdit.getChildren();
			}
			return new CPUserLibraryElement(fNameField.getText(), fIsSystemField.isSelected(), entries);
		}
		
	}
	
	public static class LoadSaveDialog extends StatusDialog implements IStringButtonAdapter, IDialogFieldListener, IListAdapter {