NPE when both populateResultLevelCache and grandTotal are set

[jihoonson]

Affected Version

All versions since 0.13.0

Description

The grandTotal doesn't have timestamp and it is filled with null in the result set. If populateResultLevelCache is set, the below code is executed and input.getTimestamp().getMillis() throws NPE.

      @Override
      public Function<Result<TimeseriesResultValue>, Object> prepareForCache(boolean isResultLevelCache)
      {
        return input -> {
          TimeseriesResultValue results = input.getValue();
          final List<Object> retVal = Lists.newArrayListWithCapacity(1 + aggs.size());

          retVal.add(input.getTimestamp().getMillis());
          for (AggregatorFactory agg : aggs) {
            retVal.add(results.getMetric(agg.getName()));
          }
          if (isResultLevelCache) {
            for (PostAggregator postAgg : query.getPostAggregatorSpecs()) {
              retVal.add(results.getMetric(postAgg.getName()));
            }
          }
          return retVal;
        };
      }