transition when we send our first padding packet, not on received
The RP circpad machine, on the relay side, should transition as soon as a padding cell is sent to the client according to the code comment. The code currently transitions on receiving a padding cell, not sending.
Copied from: https://github.com/torproject/tor/pull/1167
Gaba, I think this is Sponsor 2, because it's a circuit padding bug.
Mike or asn, please add tags.