Including rootscript in IA package will break if url is present, but empty

Nobody has claimed this yet.

Stumbled upon this issue. It is only a problem if you bundle stuff into a package.

_If you are downloading resources from an URL this does not apply!_

if you bundle a rootscript in the package you have to do the following:

a: Remove the "url" parameter, even if it is empty

or

b: Include the "url" AND the "hash" parameter

This will not work
```
"preflight": [
{
"file": "/Library/installapplications/scripts/root/05-preflight.py",
"name": "Preflight",
"type": "rootscript",
"url": ""
}
]
```
This will work

```
"preflight": [
{
"file": "/Library/installapplications/scripts/root/05-preflight.py",
"name": "Preflight",
"type": "rootscript"
}
]
```

This will also work

```
"preflight": [
{
"file": "/Library/installapplications/scripts/root/05-preflight.py",
"name": "Preflight",
"type": "rootscript",
"url": "",
"hash": "a_generated_256_hash_value"
}
]
```

The issue is easily solved by removing empty hashes from your json, which probably is a good habit anyway.

The confusion arrives since sometimes its allow with an empty hash, like this: which also will work:
```
"setupassistant": [`
{
"file": "/Library/installapplications/packages/DEPNotify-1.1.5.signed.pkg",
"hash": "a_generated_256_hash_value",
"name": "DEPNotify",
"packageid": "menu.nomad.DEPNotify",
"type": "package",
"url": "",
"version": "1.1.5"
}
]
```

It might also be that the use of generatejson.py does avoid this issue, but if you handcraft your json you have to be careful.

I think this issue is best solved by archiving this issue as part of documentation of a cornercase. I will also try to make a general addition to the documentation (as a PR) about avoiding empty hashes in your jsonfile, in case of handcrafting or copy/paste from other sources.

K

Review generatejson.py and the existing documentation for rootscript package entries, focusing on how empty url and hash fields are represented. Document the difference between bundled rootscripts and URL downloads, include the working and failing JSON examples, and explain the expected handling of empty hashes.

Written by the indexing model from the issue text.