Program: 25511
Project: 25511
Buggy source:
private void generateTierMatchesInOneBatch(final MatchRenderParameters matchRenderParameters,final MatchClipParameters emptyClipParameters,final RenderDataClient driverMatchClient) throws IOException, URISyntaxException {
  final MultiCollectionMatchStorageFunction matchStorageFunction=new MultiCollectionMatchStorageFunction(parameters.renderWeb.baseDataUrl,parameters.renderWeb.owner);
  RenderableCanvasIdPairs renderableCanvasIdPairs=null;
  for (  final HierarchicalStack tierStack : tierStacks) {
    if (tierStack.requiresMatchDerivation()) {
      final String matchCollectionName=tierStack.getMatchCollectionId().getName();
      int fromIndex=0;
      if (renderableCanvasIdPairs == null) {
        renderableCanvasIdPairs=getRenderablePairsForStack(tierStack);
      }
 else {
        fromIndex=renderableCanvasIdPairs.size();
        addCanvasPairsForStack(tierStack,renderableCanvasIdPairs);
      }
      final List<OrderedCanvasIdPair> tierPairs=renderableCanvasIdPairs.getNeighborPairs().subList(fromIndex,renderableCanvasIdPairs.size());
      for (      final OrderedCanvasIdPair tierPair : tierPairs) {
        matchStorageFunction.mapPIdToCollection(tierPair.getP().getId(),matchCollectionName);
      }
    }
  }
  if (renderableCanvasIdPairs != null) {
    LOG.info("String_Node_Str",renderableCanvasIdPairs.size());
    final long savedMatchPairCount=SIFTPointMatchClient.generateMatchesForPairs(sparkContext,renderableCanvasIdPairs,parameters.renderWeb.baseDataUrl,matchRenderParameters,parameters.match,emptyClipParameters,matchStorageFunction);
    LOG.info("String_Node_Str",savedMatchPairCount);
    updateSavedMatchPairCounts(getExistingMatchCollectionPairCounts(driverMatchClient),true);
  }
}

Fixed version (ground truth):
private void generateTierMatchesInOneBatch(final MatchRenderParameters matchRenderParameters,final MatchClipParameters emptyClipParameters,final RenderDataClient driverMatchClient) throws IOException, URISyntaxException {
  LOG.info("String_Node_Str");
  final MultiCollectionMatchStorageFunction matchStorageFunction=new MultiCollectionMatchStorageFunction(parameters.renderWeb.baseDataUrl,parameters.renderWeb.owner);
  RenderableCanvasIdPairs renderableCanvasIdPairs=null;
  for (  final HierarchicalStack tierStack : tierStacks) {
    if (tierStack.requiresMatchDerivation()) {
      final String matchCollectionName=tierStack.getMatchCollectionId().getName();
      int fromIndex=0;
      if (renderableCanvasIdPairs == null) {
        renderableCanvasIdPairs=getRenderablePairsForStack(tierStack);
      }
 else {
        fromIndex=renderableCanvasIdPairs.size();
        addCanvasPairsForStack(tierStack,renderableCanvasIdPairs);
      }
      final List<OrderedCanvasIdPair> tierPairs=renderableCanvasIdPairs.getNeighborPairs().subList(fromIndex,renderableCanvasIdPairs.size());
      for (      final OrderedCanvasIdPair tierPair : tierPairs) {
        matchStorageFunction.mapPIdToCollection(tierPair.getP().getId(),matchCollectionName);
      }
    }
  }
  if (renderableCanvasIdPairs != null) {
    LOG.info("String_Node_Str",renderableCanvasIdPairs.size());
    final long savedMatchPairCount=SIFTPointMatchClient.generateMatchesForPairs(sparkContext,renderableCanvasIdPairs,parameters.renderWeb.baseDataUrl,matchRenderParameters,parameters.match,emptyClipParameters,matchStorageFunction);
    LOG.info("String_Node_Str",savedMatchPairCount);
    final Map<String,Long> existingMatchPairCounts=getExistingMatchPairCounts(driverMatchClient);
    for (    final HierarchicalStack tierStack : tierStacks) {
      if (tierStack.requiresMatchDerivation()) {
        long matchPairCount=0;
        final String collectionName=tierStack.getMatchCollectionId().getName();
        if (existingMatchPairCounts.containsKey(collectionName)) {
          matchPairCount=existingMatchPairCounts.get(collectionName);
        }
        tierStack.setSavedMatchPairCount(matchPairCount);
        persistHierarchicalData(tierStack);
      }
    }
  }
  LOG.info("String_Node_Str");
}