fix(frames): decode pre-2D scalar gas_used in stored frame-tx receipts

src/Nethermind/Nethermind.Core.Test/Encoding/FrameTxReceiptDecoderTests.cs

@@ -6,6 +6,7 @@
 using System.Linq;
 using Nethermind.Core.Crypto;
 using Nethermind.Core.Test.Builders;
+using Nethermind.Core.Extensions;
 using Nethermind.Serialization.Rlp;
 using NUnit.Framework;
 
@@ -219,4 +220,88 @@ private static TxReceipt CreateStorageFrameReceipt(LogEntry[] unionLogs, params
 
     private static LogEntry Log(byte marker) =>
         new(TestItem.AddressB, [marker], [Keccak.Compute([marker])]);
+
+    private const string OldSingleNonCompactHex =
+        "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";
+    private const string OldSingleCompactHex =
+        "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";
+    private const string OldArrayNonCompactHex =
+        "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";
+    private const string OldArrayCompactHex =
+        "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";
+
+    [Test]
+    public void StorageDecode_PreTwoDimensionalScalarGasUsed_ReadsExecutionWithZeroState(
+        [Values(false, true)] bool compact)
+    {
+        byte[] encoded = Bytes.FromHexString(compact ? OldSingleCompactHex : OldSingleNonCompactHex);
+        RlpReader ctx = new(encoded);
+        TxReceipt[] decoded = ReceiptArrayStorageDecoder.Instance.Decode(ref ctx, RlpBehaviors.Storage);
+
+        Assert.That(decoded, Has.Length.EqualTo(1));
+        TxReceipt receipt = decoded[0];
+        Assert.That(receipt.TxType, Is.EqualTo(TxType.FrameTx));
+        Assert.That(receipt.GasUsedTotal, Is.EqualTo(51_000UL));
+        Assert.That(receipt.Payer, Is.EqualTo(TestItem.AddressA));
+        AssertFrameReceiptsEqual(receipt.FrameReceipts!,
+        [
+            new TxFrameReceipt(TxFrameReceipt.StatusSuccess, 21_000, 0, [Log(0x01)]),
+            new TxFrameReceipt(TxFrameReceipt.StatusFailure, 30_000, 0, [Log(0x02)]),
+            new TxFrameReceipt(TxFrameReceipt.StatusSkipped, 0, 0, []),
+        ]);
+    }
+
+    [Test]
+    public void StorageDecode_PreTwoDimensionalFrameReceiptBetweenRegulars_DecodesAllAndStaysAligned(
+        [Values(false, true)] bool compact)
+    {
+        byte[] encoded = Bytes.FromHexString(compact ? OldArrayCompactHex : OldArrayNonCompactHex);
+        RlpReader ctx = new(encoded);
+        TxReceipt[] decoded = ReceiptArrayStorageDecoder.Instance.Decode(ref ctx, RlpBehaviors.Storage);
+
+        Assert.That(decoded, Has.Length.EqualTo(3));
+        Assert.That(decoded[0].Sender, Is.EqualTo(TestItem.AddressD), "leading regular receipt sender");
+        Assert.That(decoded[0].GasUsedTotal, Is.EqualTo(1000UL), "leading regular receipt gas used total");
+        Assert.That(decoded[0].TxType, Is.EqualTo(TxType.Legacy));
+
+        Assert.That(decoded[1].TxType, Is.EqualTo(TxType.FrameTx));
+        AssertFrameReceiptsEqual(decoded[1].FrameReceipts!,
+        [
+            new TxFrameReceipt(TxFrameReceipt.StatusSuccess, 21_000, 0, [Log(0x01)]),
+            new TxFrameReceipt(TxFrameReceipt.StatusFailure, 30_000, 0, [Log(0x02)]),
+        ]);
+
+        Assert.That(decoded[2].Sender, Is.EqualTo(TestItem.AddressE), "trailing regular receipt sender");
+        Assert.That(decoded[2].GasUsedTotal, Is.EqualTo(2000UL), "trailing regular receipt gas used total");
+        Assert.That(decoded[2].TxType, Is.EqualTo(TxType.Legacy));
+    }
+
+    [Test]
+    public void StructRefIteration_OverPreTwoDimensionalArray_DoesNotThrowOrCorruptNeighbours(
+        [Values(false, true)] bool compact)
+    {
+        byte[] encoded = Bytes.FromHexString(compact ? OldArrayCompactHex : OldArrayNonCompactHex);
+        IReceiptRefDecoder refDecoder = compact
+            ? new CompactReceiptStorageDecoder()
+            : (IReceiptRefDecoder)new ReceiptStorageDecoder();
+
+        ReadOnlySpan<byte> body = ReceiptArrayStorageDecoder.IsCompactEncoding(encoded) ? encoded.AsSpan(1) : encoded;
+        RlpReader reader = new(body);
+        int length = reader.ReadSequenceLength();
+        int count = 0;
+        (string Sender, ulong Gas, TxType Type)[] seen = new (string, ulong, TxType)[3];
+        while (reader.Position < length)
+        {
+            refDecoder.DecodeStructRef(ref reader, RlpBehaviors.Storage, out TxReceiptStructRef current);
+            if (count < seen.Length)
+            {
+                seen[count] = (current.Sender.ToString(), current.GasUsedTotal, current.TxType);
+            }
+            count++;
+        }
+
+        Assert.That(count, Is.EqualTo(3), "every receipt must decode, including the neighbours");
+        Assert.That(seen[0], Is.EqualTo((TestItem.AddressD.ToString(), 1000UL, TxType.Legacy)));
+        Assert.That(seen[2], Is.EqualTo((TestItem.AddressE.ToString(), 2000UL, TxType.Legacy)));
+    }
 }

src/Nethermind/Nethermind.Serialization.Rlp/CompactReceiptStorageDecoder.cs

@@ -185,10 +185,7 @@ private static TxFrameReceipt[] DecodeFrameReceipts(ref RlpReader decoderContext
             {
                 int frameEnd = decoderContext.ReadSequenceLength() + decoderContext.Position;
                 byte status = decoderContext.DecodeByte();
-                int gasUsedEnd = decoderContext.ReadSequenceLength() + decoderContext.Position;
-                ulong executionGasUsed = decoderContext.DecodeULong();
-                ulong stateGasUsed = decoderContext.DecodeULong();
-                decoderContext.Check(gasUsedEnd);
+                FrameReceiptGasRlp.DecodeGasUsed(ref decoderContext, out ulong executionGasUsed, out ulong stateGasUsed);
 
                 int logsEnd = decoderContext.ReadSequenceLength() + decoderContext.Position;
                 using ArrayPoolListRef<LogEntry> frameLogs = new(4);

src/Nethermind/Nethermind.Serialization.Rlp/FrameReceiptGasRlp.cs

@@ -0,0 +1,36 @@
+// SPDX-FileCopyrightText: 2026 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+namespace Nethermind.Serialization.Rlp;
+
+internal static class FrameReceiptGasRlp
+{
+    /// <summary>
+    /// Decodes a stored frame receipt's <c>gas_used</c>, tolerating both the current
+    /// <c>[execution, state]</c> list and the pre-two-dimensional scalar written by
+    /// <c>eip8141-frame-txs-devnet7</c>.
+    /// </summary>
+    /// <remarks>
+    /// A <see cref="ulong"/> RLP scalar is always below the sequence prefix range, so the list is
+    /// unambiguously distinguished from a scalar. The scalar path attributes the whole value to the
+    /// execution dimension (<c>state = 0</c>): it preserves the per-frame total (and therefore
+    /// <c>GasUsedTotal</c> and the JSON-RPC <c>gasUsed</c>), but the receipt is not wire-faithful when
+    /// re-encoded for <c>GetReceipts</c>, where the split is carried on the wire. Read-compatibility
+    /// only, removable once no node holds devnet7-era frame-tx receipts on disk.
+    /// </remarks>
+    public static void DecodeGasUsed(ref RlpReader reader, out ulong execution, out ulong state)
+    {
+        if (reader.IsSequenceNext())
+        {
+            int gasUsedEnd = reader.ReadSequenceLength() + reader.Position;
+            execution = reader.DecodeULong();
+            state = reader.DecodeULong();
+            reader.Check(gasUsedEnd);
+        }
+        else
+        {
+            execution = reader.DecodeULong();
+            state = 0;
+        }
+    }
+}

src/Nethermind/Nethermind.Serialization.Rlp/ReceiptStorageDecoder.cs

@@ -200,10 +200,7 @@ private static TxFrameReceipt[] DecodeFrameReceipts(ref RlpReader decoderContext
             {
                 int frameEnd = decoderContext.ReadSequenceLength() + decoderContext.Position;
                 byte status = decoderContext.DecodeByte();
-                int gasUsedEnd = decoderContext.ReadSequenceLength() + decoderContext.Position;
-                ulong executionGasUsed = decoderContext.DecodeULong();
-                ulong stateGasUsed = decoderContext.DecodeULong();
-                decoderContext.Check(gasUsedEnd);
+                FrameReceiptGasRlp.DecodeGasUsed(ref decoderContext, out ulong executionGasUsed, out ulong stateGasUsed);
 
                 int logsEnd = decoderContext.ReadSequenceLength() + decoderContext.Position;
                 List<LogEntry> frameLogs = [];