Aligns the SSZ schema with PR ethereum#796 (a22fbd4), which added
targetGasLimit to PayloadAttributesV4 in the JSON spec but
left this SSZ doc behind. Without it, CLs sending the alpha-8
field over SSZ get rejected by EL SSZ decoders that still use
the old 6-field layout (off-by-8 withdrawals offset -> malformed
SSZ body).

- Add `target_gas_limit` field to `PayloadAttributesV4` to align
`engine_forkchoiceUpdatedV4`.
- Thread `val.GasLimit` from `TrackedValidator` through every
`PayloadAttributesV4` construction site (proposer RPC, blockchain FCU,
late-payload FCU, payload_attributes SSE event)
- Implements
[consensus-specs#5235](ethereum/consensus-specs#5235)
and
[execution-apis#796](ethereum/execution-apis#796).

…1297)

for ethereum/execution-apis#796 in
`glamsterdam-devnet-4`

commit 96ff773
Merge: 8a82ef5 1bb7582
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Tue Jun 2 13:33:56 2026 +0200

    Merge branch 'master' into feat/engine-payload-attrs-target-gas-limit

commit 8a82ef5
Author: Barnabas Busa <barnabas.busa@ethereum.org>
Date:   Mon May 18 15:47:00 2026 +0200

    feat(engine/ssz): add target_gas_limit to PayloadAttributesV4 wire (#11647)

    Plumbs the new TargetGasLimit field added in this PR through the
    SSZ-REST wire schema for engine_forkchoiceUpdatedV4 (PR #764).

    Without this, CLs that include target_gas_limit in the SSZ body get
    rejected as "Malformed SSZ body" because the 8 extra trailing bytes
    shift the inner withdrawals offset.

    The wire field is a required fixed-size uint64 (per execution-apis
    ssz-encoding.md), so a missing value fails SSZ decode directly — the
    V4 null-guard in PayloadAttributes.GetInvalidPayloadAttributesMessage
    remains as defense-in-depth for the JSON path.

    Changes:
    - PayloadAttributesWire gains target_gas_limit at the end of the
      container (matches execution-apis ssz-encoding.md PayloadAttributesV4).
    - SszCodec.PayloadAttributesFromWire forwards the wire ulong as long
      to PayloadAttributes.TargetGasLimit.
    - DecodeFcuV4Request roundtrip test now also asserts target_gas_limit
      survives encode/decode, using a diverse-byte value (0x0123456789ABCDEF).

commit e60c92c
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Fri May 15 08:05:21 2026 +0200

    refactor(aura): reuse inner calculator for IsGasLimitValid bound check

    `AuRaContractGasLimitOverride.IsGasLimitValid` now round-trips the
    candidate gas limit through `_innerCalculator` (a
    `TargetAdjustedGasLimitCalculator` in production): if the calculator
    returns the candidate unchanged it's within the standard parent ±
    delta range, otherwise it's been clamped. Drops the duplicated delta
    math and the `ISpecProvider` dependency added in the previous commit.

    Also strip the verbose XML doc comments added on `TargetGasLimit`,
    `PayloadAttributes.GetGasLimit`, `IGasLimitCalculator.GetGasLimit`,
    and the explanatory test comments.

commit fcd8b67
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Fri May 15 07:11:04 2026 +0200

    fix(aura): relax IsGasLimitValid for CL-supplied targetGasLimit

    `AuRaContractGasLimitOverride.GetGasLimit` prefers the CL-supplied
    `targetGasLimit` (PayloadAttributesV4) over the on-chain contract
    value, but `IsGasLimitValid` — called from `AuRaBlockProcessor` —
    still strictly required the block to match the contract. On an AuRa
    chain with an active gas-limit contract that ever activates
    EIP-7843, a producer using the override path would emit a block its
    own validator rejects.

    Accept any block gas limit within parent ± delta when it differs
    from the contract value (HeaderValidator independently enforces the
    full consensus rule). Inject `ISpecProvider` so the bound divisor is
    read from the active release spec instead of being hardcoded.

commit 6abd4a3
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Thu May 14 21:44:01 2026 +0200

    refactor(consensus): rename targetGasLimitOverride to targetGasLimit

    Align with the spec field name (`PayloadAttributesV4.targetGasLimit`).
    The "override" suffix was redundant — a non-null value already means
    override behavior. Inside `TargetAdjustedGasLimitCalculator`, reuse the
    parameter via `??=` instead of an extra local.

    Also drop the unused `using Nethermind.Xdc.Spec` in XdcGasLimitCalculator
    (left over from the previous expression-body collapse) — was failing the
    `IDE0005` lint check.

commit 74e2729
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Thu May 14 21:32:17 2026 +0200

    style(xdc): collapse XdcGasLimitCalculator.GetGasLimit to expression body

commit c3ae2b4
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Thu May 14 17:57:42 2026 +0200

    refactor(engine): simplify targetGasLimit wiring; AuRa override wins

    - Type `TargetGasLimit` as `long?` directly (was `ulong?`), dropping the
      narrowing cast and the upper-bound `> long.MaxValue` validation. Gas
      limits in Nethermind are already stored as `long`.
    - Consolidate the parameterless `PayloadAttributes.GetGasLimit()` and
      the duplicated `payloadAttributes?` access at the call site into a
      single `GetGasLimit(BlockHeader parent, IGasLimitCalculator calc)`.
      Base implementation routes `TargetGasLimit` through the calculator;
      Boost/Optimism/Taiko override to return their unadjusted value.
    - AuRa: drop the conflict warning and flip precedence — the CL's
      per-FCU `targetGasLimit` now takes priority over the on-chain
      contract value, with the contract acting as fallback when no
      override is supplied.
    - Dedup `TargetAdjustedGasLimitCalculatorTests` and the new AuRa
      override tests around small construction helpers.

commit e217c72
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Thu May 14 17:29:29 2026 +0200

    fix(engine): address review on targetGasLimit handling

    - Collapse `IGasLimitCalculator.GetGasLimit` to a single method with
      `long? targetGasLimitOverride = null` default; update all
      implementations (TargetAdjusted, AuRa, FollowOtherMiners, Optimism,
      Xdc, ManualGasLimitCalculator).
    - Reject `TargetGasLimit > long.MaxValue` in `PayloadAttributes.Validate`
      to prevent silent wrap of the `ulong? -> long?` narrowing. Cast sites
      in BlockProducerBase / TestingRpcModule now use a `checked` cast for
      defense-in-depth on paths that bypass validation.
    - AuRa contract override: when the contract returns a limit and the CL
      also supplies a `targetGasLimit`, log a warning so operators know the
      contract takes precedence; otherwise forward the override to the
      inner calculator.
    - Add focused unit tests for AuRa: contract wins (override ignored) and
      no-contract (override forwarded). Add a V4 validation case for
      `TargetGasLimit > Int64.MaxValue`.

commit 9524007
Author: lukasz.rozmej <lukasz.rozmej@gmail.com>
Date:   Thu May 14 16:54:06 2026 +0200

    feat(engine): support targetGasLimit in PayloadAttributesV4

    Implements ethereum/execution-apis#796, which adds a required
    `targetGasLimit` field to `PayloadAttributesV4` so the CL can supply
    the per-FCU gas-limit target instead of relying on the EL's static
    configuration.

    - `PayloadAttributes.TargetGasLimit` is included in `ToString`, the
      payload-id hash input, version inference, and required-field
      validation for V4 attributes.
    - `IGasLimitCalculator` gains an overload accepting an optional
      target override; `TargetAdjustedGasLimitCalculator` honors it,
      taking precedence over `BlocksConfig.TargetBlockGasLimit`.
      `AuRaContractGasLimitOverride` forwards the override to its inner
      calculator.
    - `BlockProducerBase` and `TestingRpcModule` pass the per-call target
      into the calculator so the standard gas-limit adjustment applies.