Adding the first leaf to a new empty tree fails. After the tree size is advanced to 1, add-leaf still responds 202 (or 500), not 200 like it should.

The log server will not give a 200 response for the add-leaf request until it is properly sequenced, and it checks this by asking trillian for an inclusion proof.

When the first leaf is sequenced, and the advertised tree head is advanced to size 1, the get inclusion proof rpc to trillian succeeds, but the returned inclusion proof is empty, and rejected. We intentionally don't allow inclusion proof requests from clients for tree size == 1, but for this internal request, getting an empty inclusion proof must be recognized as a valid and successful result.

Once a second leaf is added and tree head is advanced to size 2, problem likely disappears.