When saving the visualforce page, it redirects to a blank page. Can anyone advise as to why it is not redirecting to the exact url for the current page cited in the PageRefrence at the bottom?

    public class IncidentTask
    {
        public ApexPages.StandardController std;
     
        // lists the associated tasks to the Incident
        public List<BMCServiceDesk__Task__c> tasks {get; set;}
       
        public String[] records {get;set;}
        
        public IncidentTask(ApexPages.StandardController stdCtrl)
        {
         std=stdCtrl;
         tasks=[select id, Name, Subject__c =:std.getId() order by Name asc limit 400];
    
        // dynamically create set of unique Line Items from query
        Set<String> taskSet = new Set<String>();
            for (BMCServiceDesk__Task__c t : tasks)
            taskSet.add(t.Subject__c);
    
        // convert the set into a string array  
        records = new String[taskSet.size()];
        Integer i = 0;
            for (String record : taskSet) { 
            records[i] = record;
            i++;
            }
        }
      
        public PageReference save()
        {
    
         // first save the incident
            std.save();
           
         // then save the procurement tasks
            update tasks;
    
         // set current page as reference to be returned to after save commits
            PageReference result=ApexPages.currentPage();
             result.setRedirect(true);       
            
            return result;
        }
    }