Program: 57880
Project: 57880
Buggy source:
/** 
 * PLOT MERGING.
 */
@Override public boolean createRoadEast(PlotArea plotArea,Plot plot){
  ClassicPlotWorld dpw=(ClassicPlotWorld)plotArea;
  Location pos1=getPlotBottomLocAbs(plotArea,plot.getId());
  Location pos2=getPlotTopLocAbs(plotArea,plot.getId());
  int sx=pos2.getX() + 1;
  int ex=sx + dpw.ROAD_WIDTH - 1;
  int sz=pos1.getZ() - 2;
  int ez=pos2.getZ() + 2;
  LocalBlockQueue queue=plotArea.getQueue(false);
  int maxY=plotArea.getPlotManager().getWorldHeight();
  queue.setCuboid(new Location(plotArea.worldname,sx,Math.min(dpw.WALL_HEIGHT,dpw.ROAD_HEIGHT) + 1,sz + 1),new Location(plotArea.worldname,ex,Math.min(maxY,255),ez - 1),PlotBlock.get((short)0,(byte)0));
  queue.setCuboid(new Location(plotArea.worldname,sx,0,sz + 1),new Location(plotArea.worldname,ex,0,ez - 1),PlotBlock.get((short)7,(byte)0));
  queue.setCuboid(new Location(plotArea.worldname,sx,1,sz + 1),new Location(plotArea.worldname,sx,dpw.WALL_HEIGHT,ez - 1),dpw.WALL_FILLING);
  queue.setCuboid(new Location(plotArea.worldname,sx,dpw.WALL_HEIGHT + 1,sz + 1),new Location(plotArea.worldname,sx,dpw.WALL_HEIGHT + 1,ez - 1),dpw.WALL_BLOCK);
  queue.setCuboid(new Location(plotArea.worldname,ex,1,sz + 1),new Location(plotArea.worldname,ex,dpw.WALL_HEIGHT,ez - 1),dpw.WALL_FILLING);
  queue.setCuboid(new Location(plotArea.worldname,ex,dpw.WALL_HEIGHT + 1,sz + 1),new Location(plotArea.worldname,ex,dpw.WALL_HEIGHT + 1,ez - 1),dpw.WALL_BLOCK);
  queue.setCuboid(new Location(plotArea.worldname,sx + 1,1,sz + 1),new Location(plotArea.worldname,ex - 1,dpw.ROAD_HEIGHT,ez - 1),dpw.ROAD_BLOCK);
  queue.enqueue();
  return true;
}

Fixed version (ground truth):
/** 
 * PLOT MERGING.
 */
@Override public boolean createRoadEast(PlotArea plotArea,Plot plot){
  ClassicPlotWorld dpw=(ClassicPlotWorld)plotArea;
  Location pos1=getPlotBottomLocAbs(plotArea,plot.getId());
  Location pos2=getPlotTopLocAbs(plotArea,plot.getId());
  int sx=pos2.getX() + 1;
  int ex=sx + dpw.ROAD_WIDTH - 1;
  int sz=pos1.getZ() - 2;
  int ez=pos2.getZ() + 2;
  LocalBlockQueue queue=plotArea.getQueue(false);
  int maxY=plotArea.getPlotManager().getWorldHeight();
  queue.setCuboid(new Location(plotArea.worldname,sx,Math.min(dpw.WALL_HEIGHT,dpw.ROAD_HEIGHT) + 1,sz + 1),new Location(plotArea.worldname,ex,maxY,ez - 1),PlotBlock.get((short)0,(byte)0));
  queue.setCuboid(new Location(plotArea.worldname,sx,0,sz + 1),new Location(plotArea.worldname,ex,0,ez - 1),PlotBlock.get((short)7,(byte)0));
  queue.setCuboid(new Location(plotArea.worldname,sx,1,sz + 1),new Location(plotArea.worldname,sx,dpw.WALL_HEIGHT,ez - 1),dpw.WALL_FILLING);
  queue.setCuboid(new Location(plotArea.worldname,sx,dpw.WALL_HEIGHT + 1,sz + 1),new Location(plotArea.worldname,sx,dpw.WALL_HEIGHT + 1,ez - 1),dpw.WALL_BLOCK);
  queue.setCuboid(new Location(plotArea.worldname,ex,1,sz + 1),new Location(plotArea.worldname,ex,dpw.WALL_HEIGHT,ez - 1),dpw.WALL_FILLING);
  queue.setCuboid(new Location(plotArea.worldname,ex,dpw.WALL_HEIGHT + 1,sz + 1),new Location(plotArea.worldname,ex,dpw.WALL_HEIGHT + 1,ez - 1),dpw.WALL_BLOCK);
  queue.setCuboid(new Location(plotArea.worldname,sx + 1,1,sz + 1),new Location(plotArea.worldname,ex - 1,dpw.ROAD_HEIGHT,ez - 1),dpw.ROAD_BLOCK);
  queue.enqueue();
  return true;
}