Program: 121256
Project: 121256
Buggy source:
@Override protected void addTable(){
  final OutputXmlTree createOutputXmlTree=XmlmapFactory.eINSTANCE.createOutputXmlTree();
  CommandStack commandStack=externalPart.getViewer().getEditDomain().getCommandStack();
  commandStack.execute(new Command(){
    @Override public void execute(){
      if (externalPart.getViewer() instanceof XmlMapGraphicViewer) {
        XmlMapGraphicViewer viewer=(XmlMapGraphicViewer)externalPart.getViewer();
        MapperManager manager=viewer.getMapperManager();
        String outputName=manager.getMapperUI().openNewOutputCreationDialog();
        if (outputName == null) {
          return;
        }
        createOutputXmlTree.setName(outputName);
        externalData.getOutputTrees().add(createOutputXmlTree);
        MetadataTable metadataTable=new MetadataTable();
        metadataTable.setLabel(outputName);
        metadataTable.setTableName(outputName);
        mapperComponent.getMetadataList().add(metadataTable);
        mapperComponent.getProcess().addUniqueConnectionName(outputName);
        int indexOf=externalPart.getModelChildren().indexOf(createOutputXmlTree);
        if (indexOf != -1) {
          externalPart.getViewer().select((EditPart)externalPart.getChildren().get(indexOf));
        }
        if (!min_size.isEnabled()) {
          min_size.setEnabled(true);
        }
        mapperManger.getProblemsAnalyser().checkProblems(createOutputXmlTree);
        mapperManger.getMapperUI().updateStatusBar();
      }
    }
  }
);
}

Fixed version (ground truth):
@Override protected void addTable(){
  final OutputXmlTree createOutputXmlTree=XmlmapFactory.eINSTANCE.createOutputXmlTree();
  CommandStack commandStack=externalPart.getViewer().getEditDomain().getCommandStack();
  commandStack.execute(new Command(){
    @Override public void execute(){
      if (externalPart.getViewer() instanceof XmlMapGraphicViewer) {
        XmlMapGraphicViewer viewer=(XmlMapGraphicViewer)externalPart.getViewer();
        MapperManager manager=viewer.getMapperManager();
        String outputName=manager.getMapperUI().openNewOutputCreationDialog();
        if (outputName == null) {
          return;
        }
        createOutputXmlTree.setName(outputName);
        externalData.getOutputTrees().add(createOutputXmlTree);
        MetadataTable metadataTable=new MetadataTable();
        metadataTable.setLabel(outputName);
        metadataTable.setTableName(outputName);
        mapperComponent.getMetadataList().add(metadataTable);
        mapperComponent.getProcess().addUniqueConnectionName(outputName);
        int indexOf=externalPart.getModelChildren().indexOf(createOutputXmlTree);
        if (indexOf != -1) {
          externalPart.getViewer().select((EditPart)externalPart.getChildren().get(indexOf));
        }
        if (!min_size.isEnabled()) {
          min_size.setEnabled(true);
        }
        if (!externalData.getOutputTrees().isEmpty() && !externalData.getInputTrees().isEmpty()) {
          auto_map.setEnabled(true);
        }
        mapperManger.getProblemsAnalyser().checkProblems(createOutputXmlTree);
        mapperManger.getMapperUI().updateStatusBar();
      }
    }
  }
);
}