asyncreader: fix EOF error

Author: buengese

fs/asyncreader/asyncreader.go

@@ -174,6 +174,9 @@ func (a *AsyncReader) WriteTo(w io.Writer) (n int64, err error) {
 	n = 0
 	for {
 		err = a.fill()
+		if err == io.EOF {
+			return n, nil
+		}
 		if err != nil {
 			return n, err
 		}
@@ -183,6 +186,10 @@ func (a *AsyncReader) WriteTo(w io.Writer) (n int64, err error) {
 		if err != nil {
 			return n, err
 		}
+		if a.cur.err == io.EOF {
+			a.err = a.cur.err
+			return n, err
+		}
 		if a.cur.err != nil {
 			a.err = a.cur.err
 			return n, a.cur.err

fs/asyncreader/asyncreader_test.go

@@ -60,12 +60,12 @@ func TestAsyncWriteTo(t *testing.T) {
 
 	var dst = &bytes.Buffer{}
 	n, err := io.Copy(dst, ar)
-	assert.Equal(t, io.EOF, err)
+	require.NoError(t, err)
 	assert.Equal(t, int64(10), n)
 
-	// Should still return EOF
+	// Should still not return any errors
 	n, err = io.Copy(dst, ar)
-	assert.Equal(t, io.EOF, err)
+	require.NoError(t, err)
 	assert.Equal(t, int64(0), n)
 
 	err = ar.Close()