Saving file via Panel throws Exception (Call to a member function has() on array)

Describe the bug

When I’m saving a file (e.g. pdf, jpg, etc.) via the panel I got the following error.

// POST /api/pages/downloads/files/lorem-ipsum.pdf
{
    "status": "error",
    "message": "Call to a member function has() on array",
    "code": 500,
    "exception": "Error",
    "key": null,
    "file": "hasRules.php",
    "line": 43,
    "details": [],
    "route": "(.*)/files/([a-zA-Z0-9\\.\\-_%= \\+\\@\\(\\)]+)"
}

I think it’s this file:

https://github.com/distantnative/search-for-kirby/blob/main/src/models/Index/hasRules.php#L43

Steps to reproduce

Open Panel
Open a file (e.g. jpg, pdf, etc)
Edit a field of the file
Save the file
Got this exception

Expected behavior

Error message shouldn’t appear ;-)

Additional context

The data is saved correctly to the file’s content file (e.g. /content/downloads/lorem-ipsum.pdf.txt) – nothing bad happens – but the user experience isn’t good since the user gets an error message and the orange “status” bar at the bottom of the Panel (Revert | Save) does not disappear although the content is saved.

I have set the entries.files (see below) option to false. When I remove this option, I can save files without an error message.

I also tested with user fields. When I try to update a user and the entries.users option is set to false I get the error message. When I remove the option the error doesn’t occur.

Specifications

Plugin version: 1.1.0

Plugin config options:

<?php
// site/config/options/search.php
return [
'entries' => [
'pages' => 'site.index',
'files' => false,
'users' => false,
],
'fields' => [
'pages' => [
  'title',
  'searchTerms',
  'name',
  'subtitle',
  'text',
  // ...
],
],
];

Kirby version: 3.5.0
Browser: Safari

distantnative / search-for-kirby