Program: 124085
Project: 124085
Buggy source:
public void drop(DropTargetEvent event){
  if (transfer.isSupportedType(event.currentDataType)) {
    ISelection selection=transfer.getSelection();
    if (selection instanceof TreeSelection) {
      Object[] objects=((TreeSelection)selection).toArray();
      List<Object> asList=Arrays.asList(objects);
      boolean created=false;
      for (      Object obj : objects) {
        if (obj instanceof RepositoryNode) {
          RepositoryNode sourceNode=(RepositoryNode)obj;
          Item item=sourceNode.getObject().getProperty().getItem();
          if (item instanceof ContextItem) {
            ContextItem contextItem=(ContextItem)item;
            EList context=contextItem.getContext();
            Set<String> contextSet=new HashSet<String>();
            Iterator iterator=context.iterator();
            while (iterator.hasNext()) {
              Object repositoryObject=iterator.next();
              if (repositoryObject instanceof ContextTypeImpl) {
                EList contextParameters=((ContextTypeImpl)repositoryObject).getContextParameter();
                Iterator contextParas=contextParameters.iterator();
                while (contextParas.hasNext()) {
                  ContextParameterTypeImpl contextParameterType=(ContextParameterTypeImpl)contextParas.next();
                  String name=contextParameterType.getName();
                  contextSet.add(name);
                }
              }
            }
            IEditorInput editorInput=part.getEditorInput();
            if (editorInput instanceof JobEditorInput) {
              JobEditorInput jobInput=(JobEditorInput)editorInput;
              IProcess2 process=jobInput.getLoadedProcess();
              IContextManager contextManager=process.getContextManager();
              Set<String> addedContext=ConnectionContextHelper.checkAndAddContextVariables(contextItem,contextSet,contextManager,false);
              if (addedContext != null && addedContext.size() > 0) {
                ConnectionContextHelper.addContextVarForJob(process,contextItem,contextSet);
                created=true;
              }
            }
          }
        }
      }
      if (created) {
        RepositoryPlugin.getDefault().getDesignerCoreService().switchToCurContextsView();
      }
    }
  }
}

Fixed version (ground truth):
public void drop(DropTargetEvent event){
  if (transfer.isSupportedType(event.currentDataType)) {
    ISelection selection=transfer.getSelection();
    if (selection instanceof TreeSelection) {
      Object[] objects=((TreeSelection)selection).toArray();
      List<Object> asList=Arrays.asList(objects);
      boolean created=false;
      for (      Object obj : objects) {
        if (obj instanceof RepositoryNode) {
          RepositoryNode sourceNode=(RepositoryNode)obj;
          Item item=sourceNode.getObject().getProperty().getItem();
          if (item instanceof ContextItem) {
            ContextItem contextItem=(ContextItem)item;
            EList context=contextItem.getContext();
            Set<String> contextSet=new HashSet<String>();
            Iterator iterator=context.iterator();
            while (iterator.hasNext()) {
              Object repositoryObject=iterator.next();
              if (repositoryObject instanceof ContextTypeImpl) {
                EList contextParameters=((ContextTypeImpl)repositoryObject).getContextParameter();
                Iterator contextParas=contextParameters.iterator();
                while (contextParas.hasNext()) {
                  ContextParameterTypeImpl contextParameterType=(ContextParameterTypeImpl)contextParas.next();
                  String name=contextParameterType.getName();
                  contextSet.add(name);
                }
              }
            }
            IEditorInput editorInput=part.getEditorInput();
            if (editorInput instanceof JobEditorInput) {
              JobEditorInput jobInput=(JobEditorInput)editorInput;
              IProcess2 process=jobInput.getLoadedProcess();
              IContextManager contextManager=process.getContextManager();
              List<IContext> listContext=contextManager.getListContext();
              if (!ConnectionContextHelper.containsVariable(contextManager)) {
                ConnectionContextHelper.addContextVarForJob(process,contextItem,contextManager);
                created=true;
              }
 else {
                Set<String> addedContext=ConnectionContextHelper.checkAndAddContextVariables(contextItem,contextSet,contextManager,false);
                if (addedContext != null && addedContext.size() > 0) {
                  ConnectionContextHelper.addContextVarForJob(process,contextItem,contextSet);
                  created=true;
                }
              }
            }
          }
        }
      }
      if (created) {
        RepositoryPlugin.getDefault().getDesignerCoreService().switchToCurContextsView();
      }
    }
  }
}