Function validate_text_match_field 

pub fn validate_text_match_field(
    catalog: &dyn TextMatchCatalog,
    table: &str,
    field: &str,
    function_name: &str,
) -> Result<(), SQLError>

Reject silently-empty text searches up front: a match function whose field is not a real column, or is a column without a text index, previously returned zero rows with no diagnostic.