The indexes always are zero (v0.26.1 only)

[Genglun Tan]

Hi,
In version 0.26.1, the indexes for .srt or .vtt files consistently register as zero, whereas in version 0.26.0, the behavior is normal.
Here is simplified code and subtitle files:

s1, _ := astisub.OpenFile("test.srt")

for _, v := range s1.Items {
	fmt.Printf("Index: %d\n", v.Index)
}

[Quentin Renard]

I've pushed a fix on master and I've created a v0.26.2 tag, could you confirm it's working properly?

[Genglun Tan]

It works, thank for your help.