[tmigone]

Overview

Since v0.42.0 (rust-web3 -> alloy migratiuon) blocks with missing sha3Uncles fail to deserialize since alloy's AnyHeader requires it. Block fetches retry forever, so affected subgraphs stall. Block headers now deserialize through LenientHeader, which fills in the zero hash when the field is missing. LenientHeader wraps AnyHeader. It serializes identically, derefs to it, and delegates the header-trait methods to it. The other edits only convert headers built by hand.

Motivation

Regression from #6063. graph-node's rust-web3 fork defaulted sha3Uncles (bfba0af, pulled in by #2284), and the alloy migration lost that. Fixes #6738.

[Copilot]

🟡 Changes recommended

The patch is applied to every HTTP chain rather than being restricted to Celo as described.

1 open finding

• Restrict uncles_hash compatibility patch to known Celo chain IDs · New

What changed in this PR

Fixes Celo pre-Gingerbread block deserialization when sha3Uncles is absent.

Changes:

• Adds a zero-hash JSON patch for missing sha3Uncles.
• Applies response patching to HTTP block RPC calls and adds tests.

File	Description
graph/​src/​components/​ethereum/​json_patch.rs	Adds the missing-uncles-hash patch.
chain/​ethereum/​src/​transport.rs	Integrates patching into HTTP responses and tests it.

🧠 Review effort: Balanced

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[Copilot]

🟢 Approval recommended

The focused compatibility fix is consistently integrated and directly covered by regression tests.

0 open findings

1 resolved since last review

• Restrict uncles_hash compatibility patch to known Celo chain IDs

🧠 Review effort: Balanced

[dimitrovmaksim]

nit: Please use the {crate}: {description} format for the commits as well

[dimitrovmaksim]

nit: I believe AnyRpcHeader export is now unused and can be removed

Suggested change

	pub use alloy::network::{AnyHeader, AnyTxEnvelope};

[mangas]

Non-blocking nit: this test only serializes a header whose sha3Uncles is the zero default, so it can't catch a serializer that loses a real uncles hash on the way into the block cache. I checked with a mutant whose Serialize drops sha3Uncles only when it's non-zero: all three tests still pass, and a normal Ethereum block (0x1dcc…) would come back from the cache as zero.

A round-trip test with a real hash catches it (it fails on that mutant and passes on this head):

#[test]
fn round_trips_through_json() {
    let uncles = "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347";
    let json =
        CELO_PRE_GINGERBREAD_BLOCK.replacen('{', &format!(r#"{{"sha3Uncles":"{uncles}","#), 1);
    let block: AnyBlock = serde_json::from_str(&json).unwrap();
    let back: AnyBlock =
        serde_json::from_value(serde_json::to_value(&block).unwrap()).unwrap();
    assert_eq!(back.header, block.header);
}

[dimitrovmaksim]

LGTM