Zip file size increase even no file is appended

[qbma]

Hi,

I encouter a strange behaviour when I tried to open an zip file and close it without writing, the size of the zip has increased.
Here is the test case:
`package main

import (
"log"
"os"
"testing"

"github.com/juju/zip"

)

func TestAppend(t *testing.T) {
expected := int64(-1)
path := "archive.zip"

//Create archive.zip & fill it
if arc, err := os.Create(path); err != nil {
	log.Fatal("Create", err)
} else {
	w := zip.NewWriter(arc)
	if f, err := w.CreateHeader(&zip.FileHeader{
		Name:   "file.txt",
		Method: zip.Deflate,
	}); err != nil {
		log.Fatal("Create header", err)
	} else {
		f.Write([]byte("Hello world!!!"))
	}
	w.Close()
	if info, err := arc.Stat(); err != nil {
		log.Fatal("First stat", err)
	} else {
		expected = info.Size()
		log.Println("Expected=", expected)

		arc.Close()
	}
}

//Open archive.zip, get append file writer & close it without writing
if arc, err := os.OpenFile(path, os.O_RDWR, 0); err != nil {
	log.Fatal("Open", err)
} else if info, err := arc.Stat(); err != nil {
	log.Fatal("Second stat", err)
} else {
	arc.Seek(0, os.SEEK_END)
	if r, err := zip.NewReader(arc, info.Size()); err != nil {
		log.Fatal("NewReader", err)
	} else {
		w := r.Append(arc)
		w.Close()

		if info2, err := arc.Stat(); err != nil {
			log.Fatal("Third stat", err)
		} else {
			log.Println("Size=", info2.Size())
			if info2.Size() != expected {

				log.Fatal("Unexpected size")
			}
		}
		arc.Close()
	}
}

}
`

Is it a bug ?

Thanks

[skight-shen]

need to add following codes after r.Append(arc):

f, err := arc.Create(fileName)
if err != nil {
log.Fatal(err)
}
_, err = f.Write(data)
if err != nil {
log.Fatal(err)
}