TYPO3 Core

When editing the page title of a page in a workspace, I get errors:

2: SQL error: 'Incorrect integer value: '' for column `dbname`.`pages`.`tx_social_comments` at row 1' (pages:NEW66aa0c9f05a82297360389)
1: Could not be edited in offline workspace in the branch where found (failure state: 'Online record was not in a workspace!'). Auto-creation of version failed!

The tx_social_comments fields is added by my own extension that overrides the pages TCA:

'tx_social_comments' => [
    'label'   => 'Comments',
    'config' => [
        'type'          => 'inline',
        'allowed'       => 'tx_social_domain_model_comment',
        'foreign_table' => 'tx_social_domain_model_comment',

        'MM' => 'tx_social_parent_comment_mm',
        'MM_opposite_field' => 'parent',
        'MM_insert_fields' => [
            'tablenames' => 'pages'
        ],
        'MM_match_fields' => [
            'tablenames' => 'pages'
        ],
    ]
],

The SQL definition does not allow NULL values and forces the integer type:

CREATE TABLE pages (
  tx_social_comments int(11) NOT NULL DEFAULT '0'
);

This happens because the MySQL server is running in strict mode.

Now when switching to a workspace and editing the page title, an overlay record is created.
Unfortunately, the value for tx_social_comments is determined to be an empty string instead of 0 although this MM columns contain the number of MM records.

The code path in datahandler is

copyRecord_raw
-> copyRecord_procBasedOnFieldType
   -> copyRecord_processManyToMany
-> insertNewCopyVersion
   -> checkValue_SW
      -> checkValueForInline

checkValueForInline returns an empty array when it determines the incoming value is empty.

Configuring a TCA default => 0 and eval => int property does not help.

I report this for TYPO3 v11.5.38 but the code of checkValueForInline did not change up to TYPO3 v13.2, so I assume it is still there.