[Bug] There is a bug in MetadataRenderer.sol in the _generateSeed function

[spennyp]

There is a bug in MetadataRenderer.sol in the _generateSeed function which impacts psuedo-randomness:

nouns-protocol/src/token/metadata/MetadataRenderer.sol

Line 330 in 82e00ed

return uint256(keccak256(abi.encode(_tokenId, blockhash(block.number), block.coinbase, block.timestamp)));

blockhash(block.number) will always return0x0000000000000000000000000000000000000000000000000000000000000000, since the hash of the current block cannot be known when the transaction is being executed.

Instead, blockhash(block.number - 1) should be used.