internal/ethapi: correctly generate access list when no gas limit is provided

[lightclient]

Currently, geth returns an incorrect access list or fails when calling eth_createAccessList without a gas limit. This is because during each generation of the access list generation, it does a gas limit estimate. However, the estimate runs before the updated access list is set. This eventually causes the call to execute with less gas than required by the intrinsic gas formula.

Before patch:

> a = personal.listAccounts[0]
"0x9ca58ca9c146b4910075875c23c006ba0b3fe5ad"
> eth.sendTransaction({"from": a, "data": "0x6009600c60003960096000f3585854585854585854"})
"0x67F8AB20E1a548F447b1b3c3D61f18793E42f6dD"
> eth.createAccessList({"to": "0x67F8AB20E1a548F447b1b3c3D61f18793E42f6dD", "from": a}, "latest")
WARN [07-18|13:39:25.020] Served eth_createAccessList              reqid=13 duration=7.551625ms err="failed to apply transaction: 0xebe6fc97a9e69824f6a1f6c21cc8d44a59ffc65781fbf453b6b62d9325fbff9c err: intrinsic gas too low: have 27312, want 29100"
Error: failed to apply transaction: 0xebe6fc97a9e69824f6a1f6c21cc8d44a59ffc65781fbf453b6b62d9325fbff9c err: intrinsic gas too low: have 27312, want 29100
        at web3.js:6365:9(45)
        at send (web3.js:5099:62(34))
        at <eval>:1:21(9)
> eth.createAccessList({"to": "0x67F8AB20E1a548F447b1b3c3D61f18793E42f6dD", "from": a, "gas": "0xffff"}, "latest")
{
  accessList: [{
      address: "0x67F8AB20E1a548F447b1b3c3D61f18793E42f6dD",
      storageKeys: ["0x0000000000000000000000000000000000000000000000000000000000000004", "0x0000000000000000000000000000000000000000000000000000000000000007", "0x0000000000000000000000000000000000000000000000000000000000000001"]
  }],
  gasUsed: "0x72e4"
}

After patch:

> a = personal.listAccounts[0]
"0x3f9bd0812b70643544bfe736dd37d59b4896663b"
> eth.sendTransaction({"from": a, "data": "0x6009600c60003960096000f3585854585854585854"})
"0x1F9949697a37ED29a0e5B5B44daDD87927e96d9A"
> eth.createAccessList({"to": "0x1F9949697a37ED29a0e5B5B44daDD87927e96d9A", "from": a}, "latest")
{
  accessList: [{
      address: "0x1f9949697a37ed29a0e5b5b44dadd87927e96d9a",
      storageKeys: ["0x0000000000000000000000000000000000000000000000000000000000000001", "0x0000000000000000000000000000000000000000000000000000000000000004", "0x0000000000000000000000000000000000000000000000000000000000000007"]
  }],
  gasUsed: "0x72e4"
}

[rjl493456442]

But in your example, the gas usage and accesslist are identical?

[lightclient]

Yes, but I have to feed it a gas limit large enough to simulate the call and calculate the access list. The returned gas limit is just the gas used on the final call of the simulation.

[lightclient]

I updated the title so it is a bit clearer!

[rjl493456442]

@MariusVanDerWijden Any particular reason for re-estimating gas usage every time?

• If gas amount is provided, we use this amount for executing and bubble up error if it's not enough
• If gas amount is not provided, we can use a large amount(e.g. the gaslimit of current block) for executing

[holiman]

IMO this PR is fine (fixes a flaw), and it would be fine to rewrite it to be more clever in a different PR.

[fjl]

It would be better to remove the gas estimation from this loop entirely. eth_createAccessList is about finding the most complete access list, so we should just run the VM with the RPC gas cap instead of estimating gas here.

[lightclient]

Closing in favor of #25467.