Program: 149402
Project: 149402
Buggy source:
@Override public boolean perform(AbstractBuild<?,?> build,Launcher launcher,BuildListener listener) throws InterruptedException, IOException {
  TaskLogger logger=new TaskLogger(listener);
  logger.info("String_Node_Str");
  ElasticBoxCloud ebCloud=(ElasticBoxCloud)Jenkins.getInstance().getCloud(getCloud());
  if (ebCloud == null) {
    throw new IOException("String_Node_Str");
  }
  VariableResolver resolver=new VariableResolver(cloud,workspace,build,listener);
  Client client=ebCloud.createClient();
  if (!alternateAction.equals(ACTION_NONE)) {
    JSONArray instanceArray=DescriptorHelper.getInstancesAsJSONArrayResponse(client,workspace,box).getJsonArray();
    Set<String> tagSet=new HashSet<String>();
    Set<String> resolvedTags=resolver.resolveTags(tags);
    if (resolvedTags.isEmpty()) {
      tagSet.add(resolver.resolve(environment));
    }
 else {
      tagSet.addAll(resolvedTags);
    }
    List<JSONObject> existingInstances=new ArrayList<JSONObject>();
    for (    Object instance : instanceArray) {
      JSONObject json=(JSONObject)instance;
      if (json.getJSONArray("String_Node_Str").containsAll(tagSet) && !Client.InstanceState.UNAVAILABLE.equals(json.getString("String_Node_Str")) && !Client.TERMINATE_OPERATIONS.contains(json.getString("String_Node_Str"))) {
        existingInstances.add(json);
      }
    }
    if (!existingInstances.isEmpty()) {
      JSONObject instance=performAlternateAction(existingInstances,ebCloud,client,resolver,logger);
      instanceManager.setInstance(build,instance);
      return true;
    }
  }
  String instanceId=deploy(ebCloud,client,resolver,logger);
  JSONObject instance=client.getInstance(instanceId);
  Set<String> resolvedTags=resolver.resolveTags(tags);
  if (waitForCompletion && !resolvedTags.isEmpty()) {
    JSONArray instanceTags=instance.getJSONArray("String_Node_Str");
    int oldSize=instanceTags.size();
    for (    String tag : resolvedTags) {
      if (!instanceTags.contains(tag)) {
        instanceTags.add(tag);
      }
    }
    if (instanceTags.size() > oldSize) {
      instance.put("String_Node_Str",instanceTags);
      instance=client.updateInstance(instance,null);
    }
  }
  instanceManager.setInstance(build,instance);
  return true;
}

Fixed version (ground truth):
@Override public boolean perform(AbstractBuild<?,?> build,Launcher launcher,BuildListener listener) throws InterruptedException, IOException {
  TaskLogger logger=new TaskLogger(listener);
  logger.info("String_Node_Str");
  ElasticBoxCloud ebCloud=(ElasticBoxCloud)Jenkins.getInstance().getCloud(getCloud());
  if (ebCloud == null) {
    throw new IOException("String_Node_Str");
  }
  VariableResolver resolver=new VariableResolver(cloud,workspace,build,listener);
  Client client=ebCloud.createClient();
  if (!alternateAction.equals(ACTION_NONE)) {
    JSONArray instanceArray=DescriptorHelper.getInstancesAsJSONArrayResponse(client,workspace,box).getJsonArray();
    Set<String> tagSet=new HashSet<String>();
    Set<String> resolvedTags=resolver.resolveTags(tags);
    if (resolvedTags.isEmpty()) {
      tagSet.add(resolver.resolve(environment));
    }
 else {
      tagSet.addAll(resolvedTags);
    }
    List<JSONObject> existingInstances=new ArrayList<JSONObject>();
    for (    Object instance : instanceArray) {
      JSONObject json=(JSONObject)instance;
      if (json.getJSONArray("String_Node_Str").containsAll(tagSet) && !Client.InstanceState.UNAVAILABLE.equals(json.getString("String_Node_Str")) && !Client.TERMINATE_OPERATIONS.contains(json.getString("String_Node_Str"))) {
        existingInstances.add(json);
      }
    }
    if (!existingInstances.isEmpty()) {
      JSONObject instance=performAlternateAction(existingInstances,ebCloud,client,resolver,logger);
      instanceManager.setInstance(build,instance);
      return true;
    }
  }
  String instanceId=deploy(ebCloud,client,resolver,logger);
  JSONObject instance=client.getInstance(instanceId);
  Set<String> resolvedTags=resolver.resolveTags(tags);
  if (waitForCompletion && !resolvedTags.isEmpty()) {
    JSONArray instanceTags=instance.getJSONArray("String_Node_Str");
    int oldSize=instanceTags.size();
    for (    String tag : resolvedTags) {
      if (!instanceTags.contains(tag)) {
        instanceTags.add(tag);
      }
    }
    if (instanceTags.size() > oldSize) {
      instance.put("String_Node_Str",instanceTags);
      instance=client.updateInstance(instance);
    }
  }
  instanceManager.setInstance(build,instance);
  return true;
}