Documentation / Mitigation regarding untrusted input about boopickle HOT 2 OPEN

scala> val enc = new EncoderSpeed()
val enc: boopickle.EncoderSpeed = boopickle.EncoderSpeed@d59b6cb

scala> enc.writeInt(2100000000)
val res37: boopickle.Encoder = boopickle.EncoderSpeed@d59b6cb

scala> val bb = enc.asByteBuffer
val bb: java.nio.ByteBuffer = java.nio.HeapByteBuffer[pos=0 lim=4 cap=512]

scala> val dec = new DecoderSpeed(bb)
val dec: boopickle.DecoderSpeed = boopickle.DecoderSpeed@5f7509c8

scala> dec.buf.remaining
val res38: Int = 4

scala> dec.readIntArray()
java.lang.OutOfMemoryError: Java heap space

  def readIntArray(len: Int): Array[Int] = {
+     assert(buf.remaining() >= len * 4) // bail out if not
    val array = new Array[Int](len)
    buf.asIntBuffer().get(array)
    buf.position(buf.position() + len * 4)
    array
  }