/api/2/tables/scheme/23: 500 Internal Server Error at TableService::enhanceTable

Steps to reproduce

1. Open OCS API viewer in Nextcloud
2. Expand GET /ocs/v2.php/apps/tables/api/2/tables/scheme/{id}
3. Enter table ID and click "Execute"

Expected behavior

I get the table schema back

Actual behavior

I get an error:

{
  "ocs": {
    "meta": {
      "status": "failure",
      "statuscode": 996,
      "message": "Internal Server Error\n"
    },
    "data": []
  }
}

The log contains the error:

OCA\Tables\Service\TableService::enhanceTable(): Argument #2 ($userId) must be of type string, null given, called in /var/www/cloud.example.com/apps/tables/lib/Service/TableService.php on line 555 in file '/var/www/cloud.mogic.com/apps/tables/lib/Service/TableService.php' line 163

The trace:

"Exception": "TypeError",
"Message": "OCA\Tables\Service\TableService::enhanceTable(): Argument #2 ($userId) must be of type string, null given, called in /var/www/cloud.mogic.com/apps/tables/lib/Service/TableService.php on line 555",
"Code": 0,
"Trace": [
    {
        "file": "/var/www/cloud.example.com/apps/tables/lib/Service/TableService.php",
        "line": 555,
        "function": "enhanceTable",
        "class": "OCA\Tables\Service\TableService",
        "type": "->"
    },
    {
        "file": "/var/www/cloud.example.com/apps/tables/lib/Controller/ApiTablesController.php",
        "line": 115,
        "function": "getScheme",
        "class": "OCA\Tables\Service\TableService",
        "type": "->"
    },
    {
        "file": "/var/www/cloud.example.com/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 204,
        "function": "showScheme",
        "class": "OCA\Tables\Controller\ApiTablesController",
        "type": "->"
    },
    {
        "file": "/var/www/cloud.example.com/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 118,
        "function": "executeController",
        "class": "OC\AppFramework\Http\Dispatcher",
        "type": "->"
    },
[...]

Tables app version

1.0.3

Browser

Firefox 148.0

Client operating system

Debian 13

Operating system

No response

Web server

Apache

PHP engine version

PHP 8.2

Database

MariaDB

Additional info

While I see this on 1.0.3, I believe that it still exists in v1.0.5 of nextcloud tables:

• TableService::getScheme() has a nullable userId: ?string $userId = null
• it calls TableService::enhanceTable() which requires a string $userId and does not allow null there.

https://github.com/nextcloud/tables/blob/701da21f4bf7ff45861e95afd82675754774a12e/lib/Service/TableService.php#L552-L555
https://github.com/nextcloud/tables/blob/701da21f4bf7ff45861e95afd82675754774a12e/lib/Service/TableService.php#L167

Start in lib/Service/TableService.php at getScheme() around line 555 and enhanceTable() around line 163, then review the call from lib/Controller/ApiTablesController.php. Reproduce GET /ocs/v2.php/apps/tables/api/2/tables/scheme/{id} through the OCS API viewer; done means the endpoint returns the table schema instead of a 500 error caused by the nullable user ID.