paxHdrs[paxSchilyXattr+k] = v
		}
		whyOnlyPAX = "only PAX supports Xattrs"
		format.mayOnlyBe(FormatPAX)
	}
	if len(h.PAXRecords) > 0 {
		for k, v := range h.PAXRecords {
			switch _, exists := paxHdrs[k]; {
			case exists:
				continue // Do not overwrite existing records
			case h.Typeflag == TypeXGlobalHeader:
				paxHdrs[k] = v // Copy all records
			case !basicKeys[k] && !strings.HasPrefix(k, paxGNUSparse):