Program: 133425
Project: 133425
Buggy source:
/** 
 * A utility operation for processing tasks in the event loop.
 * @param currentTask The current task to be processed.
 */
private void processTask(QueuedTask currentTask){
  String name=null;
  IFile file=null;
  try {
    if (currentTask != null) {
      if ("String_Node_Str".equals(currentTask.task) || "String_Node_Str".equals(currentTask.task)) {
        name=currentTask.item.getName().replaceAll("String_Node_Str","String_Node_Str") + "String_Node_Str";
        file=currentTask.item.getProject().getFile(name);
      }
      if ("String_Node_Str".equals(currentTask.task) && !(currentTask.item instanceof ReactorAnalyzer)) {
        writeFile(currentTask.item,file);
        itemIdMap.put(currentTask.item.getId(),file.getName());
      }
 else       if ("String_Node_Str".equals(currentTask.task)) {
        Thread.currentThread();
        Thread.sleep(1000);
        if (file.exists()) {
          file.delete(true,null);
        }
        itemIdMap.remove(currentTask.item.getId());
      }
 else       if ("String_Node_Str".equals(currentTask.task)) {
        writeFile(currentTask.form,currentTask.file);
      }
 else       if ("String_Node_Str".equals(currentTask.task)) {
        String oldFile=itemIdMap.get(currentTask.item.getId());
        if (oldFile != null) {
          itemIdMap.put(currentTask.item.getId(),currentTask.file.getName());
          Thread.currentThread();
          Thread.sleep(1000);
          IProject project=currentTask.item.getProject();
          IFile oldFileHandle=project.getFile(oldFile);
          if (oldFileHandle.exists()) {
            oldFileHandle.move(currentTask.file.getProjectRelativePath(),true,null);
          }
        }
      }
    }
 else {
      Thread.currentThread();
      Thread.sleep(1000);
    }
  }
 catch (  InterruptedException|CoreException e) {
    logger.error(getClass().getName() + "String_Node_Str",e);
  }
  return;
}

Fixed version (ground truth):
/** 
 * A utility operation for processing tasks in the event loop.
 * @param currentTask The current task to be processed.
 */
private void processTask(QueuedTask currentTask){
  String name=null;
  IFile file=null;
  try {
    if (currentTask != null) {
      if ("String_Node_Str".equals(currentTask.task) || "String_Node_Str".equals(currentTask.task)) {
        name=currentTask.item.getName().replaceAll("String_Node_Str","String_Node_Str") + "String_Node_Str";
        file=currentTask.item.getProject().getFile(name);
      }
      if ("String_Node_Str".equals(currentTask.task) && !(currentTask.item instanceof ReactorAnalyzer)) {
        writeFile(currentTask.item,file);
        itemIdMap.put(currentTask.item.getId(),file.getName());
      }
 else       if ("String_Node_Str".equals(currentTask.task)) {
        Thread.currentThread();
        Thread.sleep(100);
        if (file.exists()) {
          file.delete(true,null);
        }
        itemIdMap.remove(currentTask.item.getId());
      }
 else       if ("String_Node_Str".equals(currentTask.task)) {
        writeFile(currentTask.form,currentTask.file);
      }
 else       if ("String_Node_Str".equals(currentTask.task)) {
        String oldFile=itemIdMap.get(currentTask.item.getId());
        if (oldFile != null) {
          itemIdMap.put(currentTask.item.getId(),currentTask.file.getName());
          Thread.currentThread();
          Thread.sleep(1000);
          IProject project=currentTask.item.getProject();
          IFile oldFileHandle=project.getFile(oldFile);
          if (oldFileHandle.exists()) {
            oldFileHandle.move(currentTask.file.getProjectRelativePath(),true,null);
          }
        }
      }
    }
 else {
      Thread.currentThread();
      Thread.sleep(1000);
    }
  }
 catch (  InterruptedException|CoreException e) {
    logger.error(getClass().getName() + "String_Node_Str",e);
  }
  return;
}