if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
		return nil, nil, err // EOF is okay here; exactly 0 bytes read
	}
	if bytes.Equal(tr.blk[:], zeroBlock[:]) {
		if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
			return nil, nil, err // EOF is okay here; exactly 1 block of zeros read
		}
		if bytes.Equal(tr.blk[:], zeroBlock[:]) {

			}
		}
		if v, ok := h.PAXRecords[paxKey]; ok && v == formatPAXTime(ts) {
			paxHdrs[paxKey] = v
		}
	}

	// Check basic fields.
	var blk block
	v7 := blk.toV7()
	ustar := blk.toUSTAR()
	gnu := blk.toGNU()
	verifyString(h.Name, len(v7.name()), "Name", paxPath)
	verifyString(h.Linkname, len(v7.linkName()), "Linkname", paxLinkpath)