Custom profile field data not checked sufficiently before insert into phpbb_profile_fields_data inside functions_user.php

If you create a custom profile field and do not make it a required field, you'll get an sql error when a user creates a new account but leaves the field blank. It will actually work the first time, it's every user after that will fail because a blank entry is inserted into phpbb_profile_fields_data the first time, then the insert fails for all subsequent times as an attempt to insert duplicate data. A "General Error" message appears to the user and the user account is created but not assigned to any user groups so they cannot view any forums.

I fixed it in my copy by checking if there was any actual data for the field in functions_user.php after the comment at line 254 .

if ($cp_data !== false && sizeof($cp_data))

Instead, I iterate through any fields defined in $cp_data and see if there is actually data entered for any field before performing the insert into PROFILE_FIELDS_DATA_TABLE

Maybe there is a more elegant solution but it worked for me.