}
	}
	return hdr, &tr.blk, p.err
}

// readOldGNUSparseMap reads the sparse map from the old GNU sparse format.
// The sparse map is stored in the tar header if it's small enough.
// If it's larger than four entries, then one or more extension headers are used
// to store the rest of the sparse map.
//
// The Header.Size does not reflect the size of any extended headers used.

}

// ContentCRC returns the content crc if set.
func (r *Reader) ContentCRC() map[string]string {
	if r.contentHash.Type == ChecksumNone || !r.contentHash.Valid() {
		return nil
	}
	if r.contentHash.Type.Trailing() {
		return map[string]string{r.contentHash.Type.String(): r.trailer.Get(r.contentHash.Type.Key())}
	}
	return map[string]string{r.contentHash.Type.String(): r.contentHash.Encoded}
}

	r.fileListOnce.Do(func() {
		// files and knownDirs map from a file/directory name
		// to an index into the r.fileList entry that we are
		// building. They are used to mark duplicate entries.
		files := make(map[string]int)
		knownDirs := make(map[string]int)

		// dirs[name] is true if name is known to be a directory,
		// because it appears as a prefix in a path.
		dirs := make(map[string]bool)

		for _, file := range r.File {