fix: add senders in cache if not present

[alessandromazza98]

Closes https://github.com/paradigmxyz/reth/issues/12659

Supersedes https://github.com/paradigmxyz/reth/pull/12666

Basically what happens to me is that if I use the new engine, when blocks get saved in the cache, senders is empty even though there is a transaction in the block. In fact, senders is empty only in the cache, while in the db senders is already populated correctly.

@joshieDo @mattsse what do you think of this solution?

[mattsse]

hmm, I'd like to understand first why this happens

[alessandromazza98]

hmm, I'd like to understand first why this happens

can I look for something specifically in the logs? I added a bunch of print statements to see what was happening and I was doing the following:

• send a forkchoice updated with some payload attributes (containing one tx, which I took from a random optimism block, it's a quite normal l1 block info deposit transaction) to the sequencer, with the previous block hash equal to the genesis hash. This let the sequencer start building a execution block using the payload attributes (and mempool txs but I don't send any mempool txs)
• then, i send a getPayload using the payload id sent before by the sequencer
• i then send a newPayload engine api message (using the payload that the sequencer returns at the previous point) to check that the block is valid.
• in the end i send a new forkchoice updated message without payload attributes, using the new built block hash for head, safe and finalized.

then, i do a curl (or using cast) request using eth_getBlockByHash and if i request the full block i get no transactions, if i request only tx hashes i see the one tx hash.

[alessandromazza98]

from the print statements I was able to see that when the block is built and a BlockWithSenders is built, the sender is correct (like 0xdeaddeaddead...), but I don't know why in the cache the block is passed with empty senders

[alessandromazza98]

wait, probably I found the problem and was not related to reth but to how I modified the payload building function, will let you know

[alessandromazza98]

ok problem solved, I was not including senders in the payload building function, will close the pr and the issue, thanks.