Write after Flush writes 0 bytes, no error because state is closed.

[leehinman]

With this code:

package main

import (
	"bytes"
	"fmt"

	lz4 "github.com/pierrec/lz4/v4"
)

func main() {
	var dst bytes.Buffer

	zw := lz4.NewWriter(&dst)
	n, err := zw.Write([]byte("a"))
	fmt.Printf("First Write: n: %d, err: %v\n", n, err)
	fmt.Printf("dst after first Write(): %v\n", dst.Bytes())
	zw.Flush()
	fmt.Printf("dst after Flush(): %v\n", dst.Bytes())
	n, err = zw.Write([]byte("b"))
	fmt.Printf("Second Write: n: %d, err: %v\n", n, err)
	fmt.Printf("dst after second Write(): %v\n", dst.Bytes())
	zw.Close()
	fmt.Printf("dst after Close(): %v\n", dst.Bytes())
}

You get:

First Write: n: 1, err: <nil>
dst after first Write(): [4 34 77 24 100 112 185]
dst after Flush(): [4 34 77 24 100 112 185 1 0 0 128 97]
Second Write: n: 0, err: <nil>
dst after second Write(): [4 34 77 24 100 112 185 1 0 0 128 97]
dst after Close(): [4 34 77 24 100 112 185 1 0 0 128 97 0 0 0 0 86 116 13 85]

Notice second write returns 0 for number of bytes written, no error. And data isn't written.

After a Flush, it should be possible to write again, you would just get a new block.