Provide way to submit correction tx at same nonce

[danfinlay]

I've recently spoken to several users who did this, and were able to get our Parity backend into a bad state:

Submit a tx at an account's current nonce with a gas price too low to be mined.

Parity keeps that tx in its queue, and will reject subsequent txs with higher gas and the same nonce.

Either parity should accept same-nonce transactions that haven't been mined yet, or should provide a method to unqueue unmined transactions.

[tomusdrw]

Parity will accept the transaction with higher gas price and the same nonce.
We're currently working on some UI improvements to indicate such errorneous state to the user #4958 and also give them couple of remedies like parity_removeTransaction RPC #4949

[danfinlay]

Oh, good to know, thank you!

[5chdn]

Closing as fixed as per patches in #4958 and #4949 .