confuse the Go garbage collector; they are sometimes not really
pointers but data structures encoded in a pointer type. All operations
on these types must happen in C. The proper constant to initialize an
empty such reference is 0, not nil.

These special cases were introduced in Go 1.10. For auto-updating code
from Go 1.9 and earlier, use the cftype or jni rewrites in the Go fix tool:

	}
	n, err := tw.curr.ReadFrom(r)
	if err != nil && err != ErrWriteTooLong {
		tw.err = err
	}
	return n, err
}

// Close closes the tar archive by flushing the padding, and writing the footer.
// If the current file (from a prior call to [Writer.WriteHeader]) is not fully written,
// then this returns an error.
func (tw *Writer) Close() error {
	if tw.err == ErrWriteAfterClose {
		return nil
	}

	File          []*File
	Comment       string
	decompressors map[uint16]Decompressor

	// Some JAR files are zip files with a prefix that is a bash script.
	// The baseOffset field is the start of the zip file proper.
	baseOffset int64

	// fileList is a list of files sorted by ename,
	// for use by the Open method.
	fileListOnce sync.Once
	fileList     []fileListEntry
}