Program: 128536
Project: 128536
Buggy source:
@Override public boolean validateDrop(Object target,int operation,TransferData transferType){
  if (target == null)   return false;
  super.validateDrop(target,operation,transferType);
  boolean isValid=true;
  for (  Object obj : ((StructuredSelection)getViewer().getSelection()).toArray()) {
    RepositoryNode sourceNode=(RepositoryNode)obj;
    if (sourceNode != null) {
      IRepositoryViewObject object=sourceNode.getObject();
      if (object == null) {
        return false;
      }
      if (object.getRepositoryObjectType() == ERepositoryObjectType.JOB_DOC || object.getRepositoryObjectType() == ERepositoryObjectType.JOBLET_DOC) {
        if (GlobalServiceRegister.getDefault().isServiceRegistered(IDiagramModelService.class)) {
          IDiagramModelService diagramModelService=(IDiagramModelService)GlobalServiceRegister.getDefault().getService(IDiagramModelService.class);
          if (diagramModelService != null && BusinessType.SHAP == diagramModelService.getBusinessModelType(target)) {
            return true;
          }
        }
        return false;
      }
 else       if (object.getRepositoryObjectType() == ERepositoryObjectType.ROUTINES) {
        Property property=object.getProperty();
        RoutineItem item=(RoutineItem)property.getItem();
        if (item.isBuiltIn() && target instanceof RepositoryNode) {
          return false;
        }
      }
 else       if (object.getRepositoryObjectType() == ERepositoryObjectType.SQLPATTERNS) {
        Property property=object.getProperty();
        SQLPatternItem item=(SQLPatternItem)property.getItem();
        if (item.isSystem() && target instanceof RepositoryNode) {
          return false;
        }
      }
    }
switch (operation) {
case DND.DROP_COPY:
      isValid=CopyObjectAction.getInstance().validateAction(sourceNode,(RepositoryNode)target);
    break;
case DND.DROP_MOVE:
  isValid=MoveObjectAction.getInstance().validateAction(sourceNode,(RepositoryNode)target,true);
break;
case DND.DROP_DEFAULT:
case DND.Drop:
isValid=MoveObjectAction.getInstance().validateAction(sourceNode,(RepositoryNode)target,true);
break;
default :
isValid=false;
}
}
return isValid;
}

Fixed version (ground truth):
@Override public boolean validateDrop(Object target,int operation,TransferData transferType){
  if (target == null) {
    return false;
  }
  super.validateDrop(target,operation,transferType);
  boolean isValid=true;
  for (  Object obj : ((StructuredSelection)getViewer().getSelection()).toArray()) {
    RepositoryNode sourceNode=(RepositoryNode)obj;
    if (sourceNode != null) {
      IRepositoryViewObject object=sourceNode.getObject();
      if (object == null) {
        return false;
      }
      if (object.getRepositoryObjectType() == ERepositoryObjectType.JOB_DOC || object.getRepositoryObjectType() == ERepositoryObjectType.JOBLET_DOC) {
        if (GlobalServiceRegister.getDefault().isServiceRegistered(IDiagramModelService.class)) {
          IDiagramModelService diagramModelService=(IDiagramModelService)GlobalServiceRegister.getDefault().getService(IDiagramModelService.class);
          if (diagramModelService != null && BusinessType.SHAP == diagramModelService.getBusinessModelType(target)) {
            return true;
          }
        }
        return false;
      }
 else       if (object.getRepositoryObjectType() == ERepositoryObjectType.ROUTINES) {
        Property property=object.getProperty();
        RoutineItem item=(RoutineItem)property.getItem();
        if (item.isBuiltIn() && target instanceof RepositoryNode) {
          return false;
        }
      }
 else       if (object.getRepositoryObjectType() == ERepositoryObjectType.SQLPATTERNS) {
        Property property=object.getProperty();
        SQLPatternItem item=(SQLPatternItem)property.getItem();
        if (item.isSystem() && target instanceof RepositoryNode) {
          return false;
        }
      }
    }
switch (operation) {
case DND.DROP_COPY:
      isValid=CopyObjectAction.getInstance().validateAction(sourceNode,(RepositoryNode)target);
    break;
case DND.DROP_MOVE:
  isValid=MoveObjectAction.getInstance().validateAction(sourceNode,(RepositoryNode)target,true);
break;
case DND.DROP_DEFAULT:
case DND.Drop:
isValid=MoveObjectAction.getInstance().validateAction(sourceNode,(RepositoryNode)target,true);
break;
default :
isValid=false;
}
}
return isValid;
}