Program: 66500
Project: 66500
Buggy source:
public void close() throws DataException {
  try {
    if (this.groupOutput != null) {
      for (int i=0; i < this.groupOutput.length; i++) {
        this.groupOutput[i].seek(0);
        IOUtil.writeInt(this.groupOutput[i],this.groupInstanceIndex[i]);
        this.groupOutput[i].close();
      }
      this.groupOutput=null;
    }
    if (this.aggrOutput != null) {
      for (int i=0; i < this.aggrOutput.length; i++) {
        if (this.aggrOutput[i] != null)         this.aggrOutput[i].close();
      }
      this.aggrOutput=null;
    }
    if (this.aggrIndexOutput != null) {
      for (int i=0; i < this.aggrIndexOutput.length; i++) {
        if (this.aggrIndexOutput[i] != null)         this.aggrIndexOutput[i].close();
      }
      this.aggrIndexOutput=null;
    }
    if (this.overallAggrs.size() > 0 && this.combinedAggrIndexOutput != null) {
      this.combinedAggrIndexRAOutput.seek(0);
      IOUtil.writeLong(this.combinedAggrIndexOutput,this.combinedAggrRAOutput.getOffset());
      this.combinedAggrIndexRAOutput.close();
      for (      String aggrName : overallAggrs) {
        IOUtil.writeObject(this.combinedAggrOutput,this.aggrHelper.getLatestAggrValue(aggrName));
      }
      this.combinedAggrOutput.close();
    }
    if (this.aggrHelper != null) {
      this.aggrHelper.close();
      this.aggrHelper=null;
    }
    if (this.groupBys.length == 0) {
      OutputStream out=streamManager.getOutStream(DataEngineContext.GROUP_INFO_STREAM,StreamManager.ROOT_STREAM,StreamManager.SELF_SCOPE);
      IOUtil.writeInt(out,0);
      out.close();
    }
  }
 catch (  IOException e) {
    throw new DataException(e.getLocalizedMessage(),e);
  }
}

Fixed version (ground truth):
public void close() throws DataException {
  try {
    if (this.groupOutput != null) {
      for (int i=0; i < this.groupOutput.length; i++) {
        this.groupOutput[i].seek(0);
        IOUtil.writeInt(this.groupOutput[i],this.groupInstanceIndex[i]);
        this.groupOutput[i].close();
      }
      this.groupOutput=null;
    }
    if (this.aggrOutput != null) {
      for (int i=0; i < this.aggrOutput.length; i++) {
        if (this.aggrOutput[i] != null)         this.aggrOutput[i].close();
      }
      this.aggrOutput=null;
    }
    if (this.aggrIndexOutput != null) {
      for (int i=0; i < this.aggrIndexOutput.length; i++) {
        if (this.aggrIndexOutput[i] != null)         this.aggrIndexOutput[i].close();
      }
      this.aggrIndexOutput=null;
    }
    if (this.overallAggrs.size() > 0 && this.combinedAggrIndexOutput != null) {
      this.combinedAggrIndexRAOutput.seek(0);
      IOUtil.writeLong(this.combinedAggrIndexOutput,this.combinedAggrRAOutput.getOffset());
      this.combinedAggrIndexRAOutput.close();
      for (      String aggrName : overallAggrs) {
        IOUtil.writeObject(this.combinedAggrOutput,this.aggrHelper.getLatestAggrValue(aggrName));
      }
      this.combinedAggrOutput.close();
    }
    if (this.aggrHelper != null) {
      this.aggrHelper.close();
      this.aggrHelper=null;
    }
    if (this.groupBys.length == 0 && this.streamManager != null) {
      OutputStream out=streamManager.getOutStream(DataEngineContext.GROUP_INFO_STREAM,StreamManager.ROOT_STREAM,StreamManager.SELF_SCOPE);
      IOUtil.writeInt(out,0);
      out.close();
    }
  }
 catch (  IOException e) {
    throw new DataException(e.getLocalizedMessage(),e);
  }
}