Program: 57882
Project: 57882
Buggy source:
public boolean setOutline(PlotArea plotArea,PlotId plotId,PlotBlock[] blocks){
  ClassicPlotWorld dpw=(ClassicPlotWorld)plotArea;
  if (dpw.ROAD_WIDTH == 0) {
    return false;
  }
  Plot plot=plotArea.getPlotAbs(plotId);
  Location bottom=plot.getBottomAbs();
  Location top=plot.getExtendedTopAbs();
  PseudoRandom random=new PseudoRandom();
  LocalBlockQueue queue=plotArea.getQueue(false);
  int maxY=plotArea.getPlotManager().getWorldHeight();
  if (!plot.getMerged(0)) {
    int z=bottom.getZ();
    for (int x=bottom.getX(); x <= top.getX(); x++) {
      for (int y=dpw.PLOT_HEIGHT; y <= Math.min(maxY,255); y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (!plot.getMerged(3)) {
    int x=bottom.getX();
    for (int z=bottom.getZ(); z <= top.getZ(); z++) {
      for (int y=dpw.PLOT_HEIGHT; y <= Math.min(maxY,255); y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (!plot.getMerged(2)) {
    int z=top.getZ();
    for (int x=bottom.getX(); x <= top.getX(); x++) {
      for (int y=dpw.PLOT_HEIGHT; y <= Math.min(maxY,255); y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (!plot.getMerged(1)) {
    int x=top.getX();
    for (int z=bottom.getZ(); z <= top.getZ(); z++) {
      for (int y=dpw.PLOT_HEIGHT; y <= Math.min(maxY,255); y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (plot.isBasePlot()) {
    for (    RegionWrapper region : plot.getRegions()) {
      Location pos1=new Location(plotArea.worldname,region.minX,Math.min(maxY,255),region.minZ);
      Location pos2=new Location(plotArea.worldname,region.maxX,Math.min(maxY,255),region.maxZ);
      queue.setCuboid(pos1,pos2,blocks);
    }
  }
  queue.enqueue();
  return true;
}

Fixed version (ground truth):
public boolean setOutline(PlotArea plotArea,PlotId plotId,PlotBlock[] blocks){
  ClassicPlotWorld dpw=(ClassicPlotWorld)plotArea;
  if (dpw.ROAD_WIDTH == 0) {
    return false;
  }
  Plot plot=plotArea.getPlotAbs(plotId);
  Location bottom=plot.getBottomAbs();
  Location top=plot.getExtendedTopAbs();
  PseudoRandom random=new PseudoRandom();
  LocalBlockQueue queue=plotArea.getQueue(false);
  int maxY=plotArea.getPlotManager().getWorldHeight();
  if (!plot.getMerged(0)) {
    int z=bottom.getZ();
    for (int x=bottom.getX(); x <= top.getX(); x++) {
      for (int y=dpw.PLOT_HEIGHT; y <= maxY; y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (!plot.getMerged(3)) {
    int x=bottom.getX();
    for (int z=bottom.getZ(); z <= top.getZ(); z++) {
      for (int y=dpw.PLOT_HEIGHT; y <= maxY; y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (!plot.getMerged(2)) {
    int z=top.getZ();
    for (int x=bottom.getX(); x <= top.getX(); x++) {
      for (int y=dpw.PLOT_HEIGHT; y <= maxY; y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (!plot.getMerged(1)) {
    int x=top.getX();
    for (int z=bottom.getZ(); z <= top.getZ(); z++) {
      for (int y=dpw.PLOT_HEIGHT; y <= maxY; y++) {
        queue.setBlock(x,y,z,blocks[random.random(blocks.length)]);
      }
    }
  }
  if (plot.isBasePlot()) {
    for (    RegionWrapper region : plot.getRegions()) {
      Location pos1=new Location(plotArea.worldname,region.minX,maxY,region.minZ);
      Location pos2=new Location(plotArea.worldname,region.maxX,maxY,region.maxZ);
      queue.setCuboid(pos1,pos2,blocks);
    }
  }
  queue.enqueue();
  return true;
}