Prevent overwriting of Mixnodes if the mixnode is already bonded

[tommyv1987]

Given I (the end user) have a fresh mixnode and I bond such mixnode with the relevant information

• Sphinx key
• Host
• Identity Key
• Additional Options

Then after successfully bonding the node. I attempt to bond another node with the same identity, I can overwrite the keys when using the nymd client.

Then, in the same fashion as using the Nym Wallet, I should be prevented from attempting to bond another mixnode until I unbond the existing one.

An example of a result from bonding another mixnode whilst supplying the same identity_keys.

ExecuteResult { logs: [Log { msg_index: 0, events: [Event { kind: "message", attributes: [Attribute { key: "action", value: "execute" }, Attribute { key: "module", value: "wasm" }, Attribute { key: "signer", value: "punk..." }, Attribute { key: "contract_address", value: "punk..." }] }, Event { kind: "transfer", attributes: [Attribute { key: "recipient", value: "punk..." }, Attribute { key: "sender", value: "punk..." }, Attribute { key: "amount", value: "1500000000upunk" }] }, Event { kind: "wasm", attributes: [Attribute { key: "contract_address", value: "punkaddress" }, Attribute { key: "overwritten", value: "true" }] }] }], transaction_hash: transaction::Hash(HASH) }

We should prevent this from happening because it may have the ability to lose bonding amounts.

[tommyv1987]

Steps to test:

• Build the latest mixnet contract off develop (where the code currently resides)
• Run a validator instance
• Upload the contract and instantiate the contract against the validator
• Take note off all the relevant contract details
• Create a test user (mnemonic - and punk address)
• Make sure this user has available tokens to broadcast and perform the transaction (send tokens to this account from a respective wallet)
• Have a mixnode ready to bond
  • Bond the mixnode on the first attempt - a successful log, and transaction is now on the chain
  • Now try with the same user to bond another node
    

The contract fails, and the user is not allowed to bond another node.

Attempting then to bond a gateway also fails in the contract execution: