FR 3976 then FR 1958 at Dublin
Barcelona → Dublin → Nice
Timetable, Dublin time
21:25FR 3976 from Barcelona at the gate
16:30FR 1958 to Nice leaves the gate
19 h 05 apart on the timetable, overnight
FR 1958 leaves 19 h 05 after FR 3976 arrives on the timetable: more than half a day, so not a connection we count.