Sometimes the client "recovers" already spent outputs and offers them to spend again.
This can be observed when n=2 (or more) transaction are created and at least one (but at most n-1) of them do not make it into the next block.
Afterward, the outputs of the confirmed but technically already spent transactions are falsely added to the unspent outputs again. Observable by listunspent 0.
Sometimes the client "recovers" already spent outputs and offers them to spend again.
This can be observed when
n=2(or more) transaction are created and at least one (but at mostn-1) of them do not make it into the next block.Afterward, the outputs of the confirmed but technically already spent transactions are falsely added to the unspent outputs again. Observable by
listunspent 0.