From bb35b136a1f166a75ac508e99fed9761b2be966e Mon Sep 17 00:00:00 2001
From: "lukasz.rozmej" <lukasz.rozmej@gmail.com>
Date: Tue, 8 Feb 2022 20:45:33 +0100
Subject: [PATCH] Clone BlockHeader before executing RPC

---
 .../Nethermind.Blockchain/Tracing/GethStyleTracer.cs |  4 ++--
 src/Nethermind/Nethermind.Core/Block.cs              | 12 ++++--------
 src/Nethermind/Nethermind.Core/BlockHeader.cs        |  7 +++++++
 src/Nethermind/Nethermind.Core/Bloom.cs              |  8 ++++++++
 .../Modules/Eth/EthModule.TransactionExecutor.cs     |  2 +-
 5 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/Nethermind/Nethermind.Blockchain/Tracing/GethStyleTracer.cs b/src/Nethermind/Nethermind.Blockchain/Tracing/GethStyleTracer.cs
index e8866970776..bba0d283e71 100644
--- a/src/Nethermind/Nethermind.Blockchain/Tracing/GethStyleTracer.cs
+++ b/src/Nethermind/Nethermind.Blockchain/Tracing/GethStyleTracer.cs
@@ -69,7 +69,7 @@ public GethLikeTxTrace Trace(Keccak blockHash, int txIndex, GethTraceOptions opt
             Block block = _blockTree.FindBlock(blockParameter);
             if (block is null) throw new InvalidOperationException($"Cannot find block {blockParameter}");
             tx.Hash ??= tx.CalculateHash();
-            block = block.WithReplacedBody(BlockBody.WithOneTransactionOnly(tx));
+            block = block.WithReplacedBodyCloned(BlockBody.WithOneTransactionOnly(tx));
             ITransactionProcessorAdapter currentAdapter = _transactionProcessorAdapter.CurrentAdapter;
             _transactionProcessorAdapter.CurrentAdapter = new TraceTransactionProcessorAdapter(_transactionProcessorAdapter.TransactionProcessor);
             
@@ -116,7 +116,7 @@ public GethLikeTxTrace Trace(Keccak blockHash, int txIndex, GethTraceOptions opt
             if (block == null) throw new InvalidOperationException("Only historical blocks");
             if (tx.Hash == null) throw new InvalidOperationException("Cannot trace transactions without tx hash set.");
             
-            block = block.WithReplacedBody(BlockBody.WithOneTransactionOnly(tx));
+            block = block.WithReplacedBodyCloned(BlockBody.WithOneTransactionOnly(tx));
             GethLikeBlockTracer blockTracer = new(tx.Hash, options);
             _processor.Process(block, ProcessingOptions.Trace, blockTracer.WithCancellation(cancellationToken));
             return blockTracer.BuildResult().SingleOrDefault();
diff --git a/src/Nethermind/Nethermind.Core/Block.cs b/src/Nethermind/Nethermind.Core/Block.cs
index 28dfefeb606..49d4dee65ca 100644
--- a/src/Nethermind/Nethermind.Core/Block.cs
+++ b/src/Nethermind/Nethermind.Core/Block.cs
@@ -44,16 +44,12 @@ public Block(BlockHeader blockHeader)
         {
         }
 
-        public Block WithReplacedHeader(BlockHeader newHeader)
-        {
-            return new(newHeader, Body);
-        }
+        public Block WithReplacedHeader(BlockHeader newHeader) => new(newHeader, Body);
 
-        public Block WithReplacedBody(BlockBody newBody)
-        {
-            return new(Header, newBody);
-        }
+        public Block WithReplacedBody(BlockBody newBody) => new(Header, newBody);
         
+        public Block WithReplacedBodyCloned(BlockBody newBody) => new(Header.Clone(), newBody);
+
         public BlockHeader Header { get; }
 
         public BlockBody Body { get; }
diff --git a/src/Nethermind/Nethermind.Core/BlockHeader.cs b/src/Nethermind/Nethermind.Core/BlockHeader.cs
index d7e9def93ec..c69cd8c29b3 100644
--- a/src/Nethermind/Nethermind.Core/BlockHeader.cs
+++ b/src/Nethermind/Nethermind.Core/BlockHeader.cs
@@ -128,5 +128,12 @@ public enum Format
             Short,
             FullHashAndNumber
         }
+
+        public BlockHeader Clone()
+        {
+            BlockHeader header = (BlockHeader)MemberwiseClone();
+            header.Bloom = Bloom.Clone();
+            return header;
+        }
     }
 }
diff --git a/src/Nethermind/Nethermind.Core/Bloom.cs b/src/Nethermind/Nethermind.Core/Bloom.cs
index 13db4bdf434..9e639d61be0 100644
--- a/src/Nethermind/Nethermind.Core/Bloom.cs
+++ b/src/Nethermind/Nethermind.Core/Bloom.cs
@@ -15,6 +15,7 @@
 //  along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
 
 using System;
+using System.Linq;
 using Nethermind.Core.Crypto;
 using Nethermind.Core.Extensions;
 
@@ -214,6 +215,13 @@ public BloomExtract(int index1, int index2, int index3)
         }
 
         public BloomStructRef ToStructRef() => new(Bytes);
+
+        public Bloom Clone()
+        {
+            Bloom clone = new();
+            Bytes.CopyTo(clone.Bytes, 0);
+            return clone;
+        }
     }
 
     public ref struct BloomStructRef
diff --git a/src/Nethermind/Nethermind.JsonRpc/Modules/Eth/EthModule.TransactionExecutor.cs b/src/Nethermind/Nethermind.JsonRpc/Modules/Eth/EthModule.TransactionExecutor.cs
index 76351588368..eca2e8d9410 100644
--- a/src/Nethermind/Nethermind.JsonRpc/Modules/Eth/EthModule.TransactionExecutor.cs
+++ b/src/Nethermind/Nethermind.JsonRpc/Modules/Eth/EthModule.TransactionExecutor.cs
@@ -65,7 +65,7 @@ public ResultWrapper<TResult> ExecuteTx(
 
                 using CancellationTokenSource cancellationTokenSource = new(_rpcConfig.Timeout);
                 Transaction tx = transactionCall.ToTransaction(_blockchainBridge.GetChainId());
-                return ExecuteTx(header, tx, cancellationTokenSource.Token);
+                return ExecuteTx(header.Clone(), tx, cancellationTokenSource.Token);
             }
 
             protected abstract ResultWrapper<TResult> ExecuteTx(BlockHeader header, Transaction tx, CancellationToken token);