Bug 109562 [code manipulation] "Sort Members" reorders the enum constants in enums.
Irrespective of the settings of preferences controlling Sort Members, it should not reorder enum constants because their order has semantic significance.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/SortMembersAction.java
boolean enabled= false;
		enabled= getSelectedCompilationUnit(selection) != null;
		setEnabled(enabled);
	}	
	
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction
	 */
	public void run(IStructuredSelection selection) {
		Shell shell= getShell();
		try {
			ICompilationUnit cu= getSelectedCompilationUnit(selection);
			if (cu == null) {
				return;
			}
			IType[] types= cu.getTypes();
			if (!hasMembersToSort(types)) {
				MessageDialog.openInformation(getShell(), getDialogTitle(), ActionMessages.SortMembersAction_no_members); 
				return;
			}
			
			if (!ElementValidator.check(cu, getShell(), getDialogTitle(), false)) {
				return;
			}
			
			
			IEditorPart editor= EditorUtility.openInEditor(cu);
			if (editor != null) {
				run(shell, cu, editor);
			}