Program: 109839
Project: 109839
Buggy source:
public void updateBuildProgress(BuildJob buildJob){
  Build build=buildJob.build;
  buildJob.build_currentTick++;
  World worldRef=FMLCommonHandler.instance().getMinecraftServerInstance().worldServerForDimension(buildJob.build.dim);
  if (buildJob.timeout > 0) {
    buildJob.timeout--;
    Build b=buildJob.build;
    worldRef.markBlockRangeForRenderUpdate(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ,buildJob.build_startX + b.map_sizeX,buildJob.build_startY + b.map_sizeY,buildJob.build_startZ + b.map_sizeZ);
    return;
  }
  build_rate=100000;
  build_rate=25000;
  build_rate=1000;
  build_rate=buildJob.build_rate;
  boolean replaceAir=!buildJob.useFirstPass;
  if (buildJob.neverPlaceAir)   replaceAir=false;
  int loopCount;
  Block id=null;
  buildJob.curLayerCountMax=build.map_sizeX * build.map_sizeZ;
  buildJob.doRandomBuild=false;
  try {
    if (buildJob.doRandomBuild) {
      if (worldRef.rand.nextInt(build_rand) != 0)       return;
      boolean first=true;
      int tryCount=0;
      while ((first || CoroUtilBlock.isAir(id)) && tryCount < 300) {
        tryCount++;
        first=false;
        buildJob.build_loopTickX=worldRef.rand.nextInt(build.map_sizeX);
        buildJob.build_loopTickZ=worldRef.rand.nextInt(build.map_sizeZ);
        if (((float)buildJob.curLayerCount / (float)buildJob.curLayerCountMax) > 0.9F) {
          buildJob.doRandomBuild=false;
          buildJob.build_loopTickX=0;
          buildJob.build_loopTickZ=0;
          return;
        }
        if (!buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]) {
          id=build.build_blockIDArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
          int xx=buildJob.build_startX + buildJob.build_loopTickX;
          int yy=buildJob.build_startY + buildJob.build_loopTickY;
          int zz=buildJob.build_startZ + buildJob.build_loopTickZ;
          worldRef.setBlock(xx,yy,zz,id,build.build_blockMetaArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ],buildJob.notifyFlag);
          buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]=true;
          buildJob.curLayerCount++;
        }
      }
    }
 else {
      for (loopCount=0; loopCount < build_rate; loopCount++) {
        if (buildJob.build_loopTickX >= build.map_sizeX) {
          buildJob.build_loopTickX=0;
          buildJob.build_loopTickZ++;
        }
        if (buildJob.build_loopTickZ >= build.map_sizeZ) {
          buildJob.build_loopTickZ=0;
          buildJob.build_loopTickY++;
          buildJob.curLayerCount=0;
        }
        if (buildJob.build_loopTickY >= build.map_sizeY) {
          if (buildJob.pass == 2) {
            buildComplete(buildJob);
            buildJob.buildComplete();
            if (buildJob.customGenCallback != null)             buildJob.customGenCallback.genPassPre(worldRef,buildJob,-1);
          }
 else {
            buildJob.pass++;
            buildJob.build_loopTickX=0;
            buildJob.build_loopTickZ=0;
            buildJob.build_loopTickY=0;
            buildJob.timeout=5;
            if (buildJob.customGenCallback != null)             buildJob.customGenCallback.genPassPre(worldRef,buildJob,buildJob.pass);
            if (buildJob.pass == 1) {
            }
          }
          return;
        }
        buildJob.curTick++;
        if (buildJob.pass == 0) {
          int xx=buildJob.build_startX + buildJob.build_loopTickX;
          int yy=buildJob.build_startY + buildJob.build_loopTickY;
          int zz=buildJob.build_startZ + buildJob.build_loopTickZ;
          id=build.build_blockIDArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
          boolean skipGen=false;
          BlockPos coords=new BlockPos(xx,yy,zz);
          if (buildJob.useRotationBuild) {
            if (buildJob.build.backwardsCompatibleOldRotate) {
              coords=rotate(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
            }
 else {
              coords=rotateNew(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
            }
          }
 else {
            if (buildJob.centerBuildIfNoRotate) {
              coords.add(-MathHelper.floor(build.map_sizeX / 2D),0,-MathHelper.floor(build.map_sizeZ / 2D));
            }
          }
          if (buildJob.blockIDsNoBuildOver.size() > 0) {
            Block checkCoord=worldRef.getBlock(coords.getX(),coords.getY(),coords.getZ());
            if (buildJob.blockIDsNoBuildOver.contains(checkCoord)) {
              skipGen=true;
            }
          }
          if (!skipGen) {
            worldRef.setBlock(coords.getX(),coords.getY(),coords.getZ(),Blocks.AIR,0,buildJob.notifyFlag);
          }
        }
 else {
          if (!buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]) {
            id=build.build_blockIDArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
            int meta=build.build_blockMetaArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
            int xx=buildJob.build_startX + buildJob.build_loopTickX;
            int yy=buildJob.build_startY + buildJob.build_loopTickY;
            int zz=buildJob.build_startZ + buildJob.build_loopTickZ;
            boolean skip=false;
            if (buildJob.pass == 1 && buildJob.blockIDsSkipFirstPass.contains(id)) {
              skip=true;
            }
            if (!skip && ((replaceAir || !CoroUtilBlock.isAir(id)))) {
              BlockPos coords=new BlockPos(xx,yy,zz);
              if (buildJob.useRotationBuild) {
                if (buildJob.build.backwardsCompatibleOldRotate) {
                  coords=rotate(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
                }
 else {
                  coords=rotateNew(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
                }
                int tryMeta=rotateMeta(worldRef,coords,buildJob.rotation,id,meta);
                if (tryMeta != -1)                 meta=tryMeta;
              }
 else {
                if (buildJob.centerBuildIfNoRotate) {
                  coords.add(-MathHelper.floor(build.map_sizeX / 2D),0,-MathHelper.floor(build.map_sizeZ / 2D));
                }
              }
              if (id != null || CoroUtilBlock.isAir(id)) {
                boolean skipGen=false;
                if (buildJob.blockIDsNoBuildOver.size() > 0) {
                  Block checkCoord=worldRef.getBlock(coords.getX(),coords.getY(),coords.getZ());
                  if (buildJob.blockIDsNoBuildOver.contains(checkCoord)) {
                    skipGen=true;
                  }
                }
                if (!skipGen) {
                  worldRef.setBlock(coords.getX(),coords.getY(),coords.getZ(),id,meta,2);
                }
              }
 else {
                System.out.println("String_Node_Str" + id + "String_Node_Str"+ placeholderID);
                boolean skipGen=false;
                if (buildJob.blockIDsNoBuildOver.size() > 0) {
                  Block checkCoord=worldRef.getBlock(coords.getX(),coords.getY(),coords.getZ());
                  if (buildJob.blockIDsNoBuildOver.contains(checkCoord)) {
                    skipGen=true;
                  }
                }
                if (!skipGen) {
                  worldRef.setBlock(coords.getX(),coords.getY(),coords.getZ(),placeholderID,0,buildJob.notifyFlag);
                }
              }
              buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]=true;
              buildJob.curLayerCount++;
            }
 else {
              loopCount--;
            }
          }
        }
        buildJob.build_loopTickX++;
      }
    }
  }
 catch (  Exception ex) {
    buildJob.build_active=false;
    ex.printStackTrace();
  }
}

Fixed version (ground truth):
public void updateBuildProgress(BuildJob buildJob){
  Build build=buildJob.build;
  buildJob.build_currentTick++;
  World worldRef=FMLCommonHandler.instance().getMinecraftServerInstance().worldServerForDimension(buildJob.build.dim);
  if (buildJob.timeout > 0) {
    buildJob.timeout--;
    Build b=buildJob.build;
    worldRef.markBlockRangeForRenderUpdate(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ,buildJob.build_startX + b.map_sizeX,buildJob.build_startY + b.map_sizeY,buildJob.build_startZ + b.map_sizeZ);
    return;
  }
  build_rate=100000;
  build_rate=25000;
  build_rate=1000;
  build_rate=buildJob.build_rate;
  boolean replaceAir=!buildJob.useFirstPass;
  if (buildJob.neverPlaceAir)   replaceAir=false;
  int loopCount;
  Block id=null;
  buildJob.curLayerCountMax=build.map_sizeX * build.map_sizeZ;
  buildJob.doRandomBuild=false;
  try {
    if (buildJob.doRandomBuild) {
      if (worldRef.rand.nextInt(build_rand) != 0)       return;
      boolean first=true;
      int tryCount=0;
      while ((first || isAir(id)) && tryCount < 300) {
        tryCount++;
        first=false;
        buildJob.build_loopTickX=worldRef.rand.nextInt(build.map_sizeX);
        buildJob.build_loopTickZ=worldRef.rand.nextInt(build.map_sizeZ);
        if (((float)buildJob.curLayerCount / (float)buildJob.curLayerCountMax) > 0.9F) {
          buildJob.doRandomBuild=false;
          buildJob.build_loopTickX=0;
          buildJob.build_loopTickZ=0;
          return;
        }
        if (!buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]) {
          id=build.build_blockIDArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
          int xx=buildJob.build_startX + buildJob.build_loopTickX;
          int yy=buildJob.build_startY + buildJob.build_loopTickY;
          int zz=buildJob.build_startZ + buildJob.build_loopTickZ;
          int meta=build.build_blockMetaArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
          IBlockState state=id.getStateFromMeta(meta);
          worldRef.setBlockState(new BlockPos(xx,yy,zz),state,buildJob.notifyFlag);
          buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]=true;
          buildJob.curLayerCount++;
        }
      }
    }
 else {
      for (loopCount=0; loopCount < build_rate; loopCount++) {
        if (buildJob.build_loopTickX >= build.map_sizeX) {
          buildJob.build_loopTickX=0;
          buildJob.build_loopTickZ++;
        }
        if (buildJob.build_loopTickZ >= build.map_sizeZ) {
          buildJob.build_loopTickZ=0;
          buildJob.build_loopTickY++;
          buildJob.curLayerCount=0;
        }
        if (buildJob.build_loopTickY >= build.map_sizeY) {
          if (buildJob.pass == 2) {
            buildComplete(buildJob);
            buildJob.buildComplete();
            if (buildJob.customGenCallback != null)             buildJob.customGenCallback.genPassPre(worldRef,buildJob,-1);
          }
 else {
            buildJob.pass++;
            buildJob.build_loopTickX=0;
            buildJob.build_loopTickZ=0;
            buildJob.build_loopTickY=0;
            buildJob.timeout=5;
            if (buildJob.customGenCallback != null)             buildJob.customGenCallback.genPassPre(worldRef,buildJob,buildJob.pass);
            if (buildJob.pass == 1) {
            }
          }
          return;
        }
        buildJob.curTick++;
        if (buildJob.pass == 0) {
          int xx=buildJob.build_startX + buildJob.build_loopTickX;
          int yy=buildJob.build_startY + buildJob.build_loopTickY;
          int zz=buildJob.build_startZ + buildJob.build_loopTickZ;
          id=build.build_blockIDArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
          boolean skipGen=false;
          BlockPos coords=new BlockPos(xx,yy,zz);
          if (buildJob.useRotationBuild) {
            if (buildJob.build.backwardsCompatibleOldRotate) {
              coords=rotate(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
            }
 else {
              coords=rotateNew(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
            }
          }
 else {
            if (buildJob.centerBuildIfNoRotate) {
              coords.add(-MathHelper.floor(build.map_sizeX / 2D),0,-MathHelper.floor(build.map_sizeZ / 2D));
            }
          }
          if (buildJob.blockIDsNoBuildOver.size() > 0) {
            Block checkCoord=worldRef.getBlockState(coords).getBlock();
            if (buildJob.blockIDsNoBuildOver.contains(checkCoord)) {
              skipGen=true;
            }
          }
          if (!skipGen) {
            worldRef.setBlockState(coords,Blocks.AIR.getDefaultState(),buildJob.notifyFlag);
          }
        }
 else {
          if (!buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]) {
            id=build.build_blockIDArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
            int meta=build.build_blockMetaArr[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ];
            int xx=buildJob.build_startX + buildJob.build_loopTickX;
            int yy=buildJob.build_startY + buildJob.build_loopTickY;
            int zz=buildJob.build_startZ + buildJob.build_loopTickZ;
            boolean skip=false;
            if (buildJob.pass == 1 && buildJob.blockIDsSkipFirstPass.contains(id)) {
              skip=true;
            }
            if (!skip && ((replaceAir || !isAir(id)))) {
              BlockPos coords=new BlockPos(xx,yy,zz);
              if (buildJob.useRotationBuild) {
                if (buildJob.build.backwardsCompatibleOldRotate) {
                  coords=rotate(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
                }
 else {
                  coords=rotateNew(coords,buildJob.direction,new Vec3d(buildJob.build_startX,buildJob.build_startY,buildJob.build_startZ),new Vec3d(build.map_sizeX,build.map_sizeY,build.map_sizeZ));
                }
                int tryMeta=rotateMeta(worldRef,coords,buildJob.rotation,id,meta);
                if (tryMeta != -1)                 meta=tryMeta;
              }
 else {
                if (buildJob.centerBuildIfNoRotate) {
                  coords.add(-MathHelper.floor(build.map_sizeX / 2D),0,-MathHelper.floor(build.map_sizeZ / 2D));
                }
              }
              if (id != null || isAir(id)) {
                boolean skipGen=false;
                if (buildJob.blockIDsNoBuildOver.size() > 0) {
                  Block checkCoord=worldRef.getBlockState(coords).getBlock();
                  if (buildJob.blockIDsNoBuildOver.contains(checkCoord)) {
                    skipGen=true;
                  }
                }
                if (!skipGen) {
                  IBlockState state=id.getStateFromMeta(meta);
                  worldRef.setBlockState(coords,state,2);
                }
              }
 else {
                System.out.println("String_Node_Str" + id + "String_Node_Str"+ placeholderID);
                boolean skipGen=false;
                if (buildJob.blockIDsNoBuildOver.size() > 0) {
                  Block checkCoord=worldRef.getBlockState(coords).getBlock();
                  if (buildJob.blockIDsNoBuildOver.contains(checkCoord)) {
                    skipGen=true;
                  }
                }
                if (!skipGen) {
                  worldRef.setBlockState(coords,placeholderID.getDefaultState(),buildJob.notifyFlag);
                }
              }
              buildJob.build_blockPlaced[buildJob.build_loopTickX][buildJob.build_loopTickY][buildJob.build_loopTickZ]=true;
              buildJob.curLayerCount++;
            }
 else {
              loopCount--;
            }
          }
        }
        buildJob.build_loopTickX++;
      }
    }
  }
 catch (  Exception ex) {
    buildJob.build_active=false;
    ex.printStackTrace();
  }
}