// receive. However, this may allocate less than len(p).
		want := int64(len(p))
		if b.expected > want {
			want = b.expected
		}
		chunk := b.lastChunkOrAlloc(want)
		n := copy(chunk[b.w:], p)
		p = p[n:]
		b.w += n
		b.size += n
		b.expected -= int64(n)
	}
	return ntotal, nil
}

func (b *http2dataBuffer) lastChunkOrAlloc(want int64) []byte {
	if len(b.chunks) != 0 {