Method setBlockState

src/main/java/net/minecraft/world/chunk/Chunk.java:660–779

(BlockPos pos, IBlockState state)

    }

    public IBlockState setBlockState(BlockPos pos, IBlockState state)
    {
        int i = pos.getX() & 15;
        int j = pos.getY();
        int k = pos.getZ() & 15;
        int l = k << 4 | i;

        if (j >= this.precipitationHeightMap[l] - 1)
        {
            this.precipitationHeightMap[l] = -999;
        }

        int i1 = this.heightMap[l];
        IBlockState iblockstate = this.getBlockState(pos);

        if (iblockstate == state)
        {
            return null;
        }
        else
        {
            Block block = state.getBlock();
            Block block1 = iblockstate.getBlock();
            ExtendedBlockStorage extendedblockstorage = this.storageArrays[j >> 4];
            boolean flag = false;

            if (extendedblockstorage == null)
            {
                if (block == Blocks.air)
                {
                    return null;
                }

                extendedblockstorage = this.storageArrays[j >> 4] = new ExtendedBlockStorage(j >> 4 << 4, !this.worldObj.provider.getHasNoSky());
                flag = j >= i1;
            }

            extendedblockstorage.set(i, j & 15, k, state);

            if (block1 != block)
            {
                if (!this.worldObj.isRemote)
                {
                    block1.breakBlock(this.worldObj, pos, iblockstate);
                }
                else if (block1 instanceof ITileEntityProvider)
                {
                    this.worldObj.removeTileEntity(pos);
                }
            }

            if (extendedblockstorage.getBlockByExtId(i, j & 15, k) != block)
            {
                return null;
            }
            else
            {
                if (flag)