Program: 189146
Project: 189146
Buggy source:
private void layout(){
  User currentUser=((HeadsUpSession)getSession()).getUser();
  boolean userHasPermission=Manager.getSecurityInstance().userHasPermission(currentUser,new MilestoneEditPermission(),project);
  Object o=getDefaultModel().getObject();
  WebMarkupContainer commentTitle=new WebMarkupContainer("String_Node_Str");
  if (o instanceof Comment) {
    comment=(Comment)o;
    add(new Image("String_Node_Str",new ResourceReference(HeadsUpPage.class,"String_Node_Str")));
    commentTitle.add(new GravatarLinkPanel("String_Node_Str",comment.getUser(),ICON_EDGE_LENGTH));
    PageParameters params=new PageParameters();
    params.put("String_Node_Str",project);
    params.put("String_Node_Str",milestone.getName());
    params.put("String_Node_Str",comment.getId());
    Link edit=new BookmarkablePageLink("String_Node_Str",EditComment.class,params);
    commentTitle.add(edit.setVisible(userHasPermission));
    params.add("String_Node_Str",comment.getUser().getUsername());
    params.add("String_Node_Str","String_Node_Str");
    BookmarkablePageLink usernameLink=new BookmarkablePageLink("String_Node_Str",page.getPageClass("String_Node_Str"),params);
    usernameLink.add(new Label("String_Node_Str",comment.getUser().getFullnameOrUsername()));
    commentTitle.add(usernameLink);
    commentTitle.add(new Label("String_Node_Str",new FormattedDateModel(comment.getCreated(),((HeadsUpSession)getSession()).getTimeZone())));
    add(new Label("String_Node_Str",new MarkedUpTextModel(comment.getComment(),project)).setEscapeModelStrings(false));
    Link remove=new Link("String_Node_Str"){
      @Override public void onClick(){
        Storage storage=Manager.getStorageInstance();
        Comment comm=(Comment)((HibernateStorage)storage).merge(comment);
        milestone.getComments().remove(comm);
        Milestone mile=(Milestone)((HibernateStorage)storage).merge(milestone);
        commentList.remove(comm);
        mile.setUpdated(new Date());
        ((HibernateStorage)storage).delete(comm);
      }
    }
;
    commentTitle.add(remove.setVisible(userHasPermission));
  }
 else {
    commentTitle.setVisible(false);
    add(new WebMarkupContainer("String_Node_Str").setVisible(false));
  }
  add(commentTitle);
}

Fixed version (ground truth):
private void layout(){
  User currentUser=((HeadsUpSession)getSession()).getUser();
  boolean userHasPermission=Manager.getSecurityInstance().userHasPermission(currentUser,new MilestoneEditPermission(),project);
  Object o=getDefaultModel().getObject();
  WebMarkupContainer commentTitle=new WebMarkupContainer("String_Node_Str");
  if (o instanceof Comment) {
    comment=(Comment)o;
    add(new Image("String_Node_Str",new ResourceReference(HeadsUpPage.class,"String_Node_Str")));
    commentTitle.add(new GravatarLinkPanel("String_Node_Str",comment.getUser(),ICON_EDGE_LENGTH));
    PageParameters params=new PageParameters();
    params.put("String_Node_Str",project);
    params.put("String_Node_Str",milestone.getName());
    params.put("String_Node_Str",comment.getId());
    Link edit=new BookmarkablePageLink("String_Node_Str",EditComment.class,params);
    commentTitle.add(edit.setVisible(userHasPermission));
    params.add("String_Node_Str",comment.getUser().getUsername());
    params.add("String_Node_Str","String_Node_Str");
    BookmarkablePageLink usernameLink=new BookmarkablePageLink("String_Node_Str",RenderUtil.getPageClass("String_Node_Str"),params);
    usernameLink.add(new Label("String_Node_Str",comment.getUser().getFullnameOrUsername()));
    commentTitle.add(usernameLink);
    commentTitle.add(new Label("String_Node_Str",new FormattedDateModel(comment.getCreated(),((HeadsUpSession)getSession()).getTimeZone())));
    add(new Label("String_Node_Str",new MarkedUpTextModel(comment.getComment(),project)).setEscapeModelStrings(false));
    Link remove=new Link("String_Node_Str"){
      @Override public void onClick(){
        Storage storage=Manager.getStorageInstance();
        Comment comm=(Comment)((HibernateStorage)storage).merge(comment);
        milestone.getComments().remove(comm);
        Milestone mile=(Milestone)((HibernateStorage)storage).merge(milestone);
        commentList.remove(comm);
        mile.setUpdated(new Date());
        ((HibernateStorage)storage).delete(comm);
      }
    }
;
    commentTitle.add(remove.setVisible(userHasPermission));
  }
 else {
    commentTitle.setVisible(false);
    add(new WebMarkupContainer("String_Node_Str").setVisible(false));
  }
  add(commentTitle);
}