Program: 97394
Project: 97394
Buggy source:
@Override public void performDrop(final DropTargetEvent event){
  Artifact parentArtifact=getSelectedArtifact(event);
  if (parentArtifact == null && selectedBranch != null) {
    try {
      parentArtifact=OseeSystemArtifacts.getDefaultHierarchyRootArtifact(selectedBranch);
    }
 catch (    Exception ex) {
      OseeLog.log(getClass(),OseeLevel.SEVERE_POPUP,ex);
    }
  }
  if (parentArtifact != null) {
    if (ArtifactTransfer.getInstance().isSupportedType(event.currentDataType)) {
      ArtifactData artData=ArtifactTransfer.getInstance().nativeToJava(event.currentDataType);
      final Artifact[] artifactsToBeRelated=artData.getArtifacts();
      if (artifactsToBeRelated != null && artifactsToBeRelated.length > 0 && !artifactsToBeRelated[0].getBranch().equals(parentArtifact.getBranch())) {
        MessageDialogWithToggle result=MessageDialogWithToggle.openYesNoQuestion(viewPart.getViewSite().getShell(),"String_Node_Str","String_Node_Str","String_Node_Str",true,null,null);
        InterArtifactExplorerDropHandlerOperation interDropHandler=new InterArtifactExplorerDropHandlerOperation(parentArtifact,artifactsToBeRelated,true,result.getReturnCode() == IDialogConstants.YES_ID,result.getToggleState());
        Operations.executeAsJob(interDropHandler,true);
      }
 else       if (isValidForArtifactDrop(event) && MessageDialog.openQuestion(viewPart.getViewSite().getShell(),"String_Node_Str","String_Node_Str" + parentArtifact.getName() + "String_Node_Str")) {
        try {
          SkynetTransaction transaction=TransactionManager.createTransaction(parentArtifact.getBranch(),"String_Node_Str");
          for (          Artifact artifact : artifactsToBeRelated) {
            Artifact currentParent=artifact.getParent();
            if (currentParent != null) {
              currentParent.deleteRelation(CoreRelationTypes.Default_Hierarchical__Child,artifact);
              currentParent.persist(transaction);
            }
            parentArtifact.addChild(RelationOrderBaseTypes.USER_DEFINED,artifact);
            parentArtifact.persist(transaction);
          }
          transaction.execute();
        }
 catch (        OseeCoreException ex) {
          OseeLog.log(getClass(),OseeLevel.SEVERE_POPUP,ex);
        }
      }
    }
 else     if (FileTransfer.getInstance().isSupportedType(event.currentDataType)) {
      Object object=FileTransfer.getInstance().nativeToJava(event.currentDataType);
      if (object instanceof String[]) {
        String[] items=(String[])object;
        File importFile=new File(items[0]);
        ArtifactImportWizard wizard=new ArtifactImportWizard();
        wizard.setImportFile(importFile);
        wizard.setDestinationArtifact(parentArtifact);
        Wizards.initAndOpen(wizard,viewPart,new ArtifactStructuredSelection(parentArtifact));
      }
    }
  }
}

Fixed version (ground truth):
@Override public void performDrop(final DropTargetEvent event){
  Artifact parentArtifact=getSelectedArtifact(event);
  if (parentArtifact == null && selectedBranch != null) {
    try {
      parentArtifact=OseeSystemArtifacts.getDefaultHierarchyRootArtifact(selectedBranch);
    }
 catch (    Exception ex) {
      OseeLog.log(getClass(),OseeLevel.SEVERE_POPUP,ex);
    }
  }
  if (parentArtifact != null) {
    if (ArtifactTransfer.getInstance().isSupportedType(event.currentDataType)) {
      ArtifactData artData=ArtifactTransfer.getInstance().nativeToJava(event.currentDataType);
      final Artifact[] artifactsToBeRelated=artData.getArtifacts();
      if (artifactsToBeRelated != null && artifactsToBeRelated.length > 0 && !artifactsToBeRelated[0].getBranch().equals(parentArtifact.getBranch())) {
        InterArtifactExplorerDropHandlerOperation interDropHandler=new InterArtifactExplorerDropHandlerOperation(parentArtifact,artifactsToBeRelated,true);
        Operations.executeAsJob(interDropHandler,true);
      }
 else       if (isValidForArtifactDrop(event) && MessageDialog.openQuestion(viewPart.getViewSite().getShell(),"String_Node_Str","String_Node_Str" + parentArtifact.getName() + "String_Node_Str")) {
        try {
          SkynetTransaction transaction=TransactionManager.createTransaction(parentArtifact.getBranch(),"String_Node_Str");
          for (          Artifact artifact : artifactsToBeRelated) {
            Artifact currentParent=artifact.getParent();
            if (currentParent != null) {
              currentParent.deleteRelation(CoreRelationTypes.Default_Hierarchical__Child,artifact);
              currentParent.persist(transaction);
            }
            parentArtifact.addChild(RelationOrderBaseTypes.USER_DEFINED,artifact);
            parentArtifact.persist(transaction);
          }
          transaction.execute();
        }
 catch (        OseeCoreException ex) {
          OseeLog.log(getClass(),OseeLevel.SEVERE_POPUP,ex);
        }
      }
    }
 else     if (FileTransfer.getInstance().isSupportedType(event.currentDataType)) {
      Object object=FileTransfer.getInstance().nativeToJava(event.currentDataType);
      if (object instanceof String[]) {
        String[] items=(String[])object;
        File importFile=new File(items[0]);
        ArtifactImportWizard wizard=new ArtifactImportWizard();
        wizard.setImportFile(importFile);
        wizard.setDestinationArtifact(parentArtifact);
        Wizards.initAndOpen(wizard,viewPart,new ArtifactStructuredSelection(parentArtifact));
      }
    }
  }
}