Wrong uri when DirectoryNamer returns '0'

[huynguyen93]

Bug Report

Q	A
BC Break	no
Bundle version	1.21.1
Symfony version	6.0
PHP version	8.1

Summary

I have a custom DirectoryNamerInterface

class UserFileDirectoryNamer implements DirectoryNamerInterface
{
    public function directoryName($object, PropertyMapping $mapping): string
    {
        return '0';
    }
}

The files are uploaded to correct folder (/uploads/0/file.txt), but when I get the uri, it's wrong (/uploads/file.txt)

How to reproduce

Make a DirectoryNamer as above

Expected behavior

the uri should be correct (/uploads/0/file.txt)

I took a look at AbstractStorage, the bug is probably caused by this check $path = !empty($dir) ? $dir.'/'.$filename : $filename;

!empty('0') returns false;

[garak]

Duplicate of #1111