Leading slash in file name when inside a box

[ItalyPaleAle]

Easier to explain if I show the code directly.

Suppose I have a folder /ui/assets that contains various files, including foo.txt:

assetsBox, err := pkger.Open("/ui/assets")
if err != nil {
    return err
}
f, err := assetsBox.Open("foo.txt")

I would expect the call above to open the file foo.txt.

• If the files are being read from the filesystem (e.g. while in development), the call above works
• If the files are read from a package (after having compiled the app), the call above returns a "file not found" error

In both cases,adding a leading slash (assetsBox.Open("/foo.txt")) fixes it. However, this behavior is inconsistent with the fs module in Go, when reading a directory.