“Parity Ethereum v2.5.11-stable is an emergency patch release that adds the missing eip1344_transition for mainnet – Users are advised to update as soon as possible to prevent any issues with the imminent Istanbul hardfork,” they say.
The EIP in question “proposes to add an opcode to retrieve the chain id of the chain that the block has been mined on.
This would allow smart contract to validate signatures that use replay protection (as proposed in EIP-155 14).
Currently the only way is to hardcode the chain id into the smart contract. This poses a problem in case of a hardfork.
This opcode would allow multi signature contracts that use signatures to implement better replay protection and increase security.”
Just how they forgot to include a whole EIP is not clear. Nor is it clear how they only found out hours before the upgrade of the entire ethereum network which is meant to activate tomorrow.
Nor is it clear why anyone is using this client at all. There are plenty others that are not under the payroll of a different blockchain project that aims to provide the same capabilities as ethereum.
The reason is obviously because of inertia presumably as the Parity team initially was focused solely on eth, but now running their client is not much different than bitcoiners running a client launched by the BCH dev team, or the latter running a client by Blockstream.
Hence presumably why they managed to forget this EIP and somehow remembered just before the “hardfork.”