TYPO3 Core

Adding records as default values does not work for TCA type=group with internal_type=db and configured MM-relation.

Not working:

&defVals[tx_ext_domain_model_foo][bars]=tx_ext_domain_model_bar_1,tx_ext_domain_model_bar_3

I looked into it and found out, that the vanilla uid of the record is passed as MMuid to the RelationHandler. This leads to a database lookup of the not yet persisted record relation and an empty result. Passing 0 leads to the desired list reading and correct fetching.

I suggest changing this line to something like

$result['command'] === 'new' ? 0 : $result['databaseRow']['uid'];