// MaterialData matdata;
// BlockState blockstate;
// Block mechanism;
// blockstate = mechanism.getBlockState();

// save the block state and fire an update
blockstate.setData(matdata);
blockstate.update(true);

// FIXME BUKKIT-1858
// if (!UNOFFICIAL_SERVER_WITH_WORKAROUND) {
if (true) {
    // Determine attached block
    BlockFace face = BlockFace.SELF;
    if (matdata instanceof Attachable) {
        face = ((Attachable) matdata).getAttachedFace();
    } else if (matdata instanceof PressurePlate) {
        face = BlockFace.DOWN;
    }

    Block atch = mechanism.getRelative(face);
    BlockState stat = atch.getState(); // Store the state, to reapply it
    // Trying to update with no changes does nothing, so we first set it to air, with no physics (so that the mechanism doesn't come off).
    atch.setTypeId(0, false);
    stat.update(true); // Reapply the state
}