Fix/arg out of range SnapProvider.AddAccountRange (#7060)

Co-authored-by: Lukasz Rozmej <lukasz.rozmej@gmail.com>

src/Nethermind/Nethermind.Synchronization.Test/SnapSync/SnapProviderTests.cs

@@ -0,0 +1,62 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using FluentAssertions;
+using Nethermind.Blockchain;
+using Nethermind.Core.Crypto;
+using Nethermind.Core.Extensions;
+using Nethermind.Db;
+using Nethermind.Logging;
+using Nethermind.State.Snap;
+using Nethermind.Synchronization.SnapSync;
+using Nethermind.Trie;
+using NSubstitute;
+using NUnit.Framework;
+using System;
+using System.Collections.Generic;
+
+namespace Nethermind.Synchronization.Test.SnapSync;
+
+[TestFixture]
+public class SnapProviderTests
+{
+
+    [Test]
+    public void AddAccountRange_AccountListIsEmpty_ThrowArgumentException()
+    {
+        MemDb db = new();
+        IDbProvider dbProvider = new DbProvider();
+        dbProvider.RegisterDb(DbNames.State, db);
+        using ProgressTracker progressTracker = new(Substitute.For<IBlockTree>(), dbProvider.GetDb<IDb>(DbNames.State), LimboLogs.Instance);
+        dbProvider.RegisterDb(DbNames.Code, new MemDb());
+        SnapProvider sut = new(progressTracker, dbProvider.CodeDb, new NodeStorage(dbProvider.StateDb), LimboLogs.Instance);
+
+        Assert.That(
+            () => sut.AddAccountRange(
+                0,
+                Keccak.Zero,
+                Keccak.Zero,
+                Array.Empty<PathWithAccount>(),
+                Array.Empty<byte[]>().AsReadOnly()), Throws.ArgumentException);
+    }
+
+
+    [Test]
+    public void AddAccountRange_ResponseHasEmptyListOfAccountsAndOneProof_ReturnsExpiredRootHash()
+    {
+        MemDb db = new();
+        IDbProvider dbProvider = new DbProvider();
+        dbProvider.RegisterDb(DbNames.State, db);
+        using ProgressTracker progressTracker = new(Substitute.For<IBlockTree>(), dbProvider.GetDb<IDb>(DbNames.State), LimboLogs.Instance);
+        dbProvider.RegisterDb(DbNames.Code, new MemDb());
+        AccountRange accountRange = new(Keccak.Zero, Keccak.Zero, Keccak.MaxValue);
+        using AccountsAndProofs accountsAndProofs = new();
+        accountsAndProofs.PathAndAccounts = new List<PathWithAccount>().ToPooledList();
+        accountsAndProofs.Proofs = new List<byte[]> { new byte[] { 0x0 } }.ToPooledList();
+
+        SnapProvider sut = new(progressTracker, dbProvider.CodeDb, new NodeStorage(dbProvider.StateDb), LimboLogs.Instance);
+
+        sut.AddAccountRange(accountRange, accountsAndProofs).Should().Be(AddRangeResult.ExpiredRootHash);
+    }
+
+}

src/Nethermind/Nethermind.Synchronization/SnapSync/SnapProvider.cs

@@ -51,15 +51,21 @@ public AddRangeResult AddAccountRange(AccountRange request, AccountsAndProofs re
         {
             AddRangeResult result;
 
-            if (response.PathAndAccounts.Count == 0 && response.Proofs.Count == 0)
+            if (response.PathAndAccounts.Count == 0)
             {
                 _logger.Trace($"SNAP - GetAccountRange - requested expired RootHash:{request.RootHash}");
 
                 result = AddRangeResult.ExpiredRootHash;
             }
             else
             {
-                result = AddAccountRange(request.BlockNumber.Value, request.RootHash, request.StartingHash, response.PathAndAccounts, response.Proofs, hashLimit: request.LimitHash);
+                result = AddAccountRange(
+                    request.BlockNumber.Value,
+                    request.RootHash,
+                    request.StartingHash,
+                    response.PathAndAccounts,
+                    response.Proofs,
+                    hashLimit: request.LimitHash);
 
                 if (result == AddRangeResult.OK)
                 {
@@ -73,8 +79,16 @@ public AddRangeResult AddAccountRange(AccountRange request, AccountsAndProofs re
             return result;
         }
 
-        public AddRangeResult AddAccountRange(long blockNumber, in ValueHash256 expectedRootHash, in ValueHash256 startingHash, IReadOnlyList<PathWithAccount> accounts, IReadOnlyList<byte[]> proofs = null, in ValueHash256? hashLimit = null!)
+        public AddRangeResult AddAccountRange(
+            long blockNumber,
+            in ValueHash256 expectedRootHash,
+            in ValueHash256 startingHash,
+            IReadOnlyList<PathWithAccount> accounts,
+            IReadOnlyList<byte[]> proofs = null,
+            in ValueHash256? hashLimit = null!)
         {
+            if (accounts.Count == 0)
+                throw new ArgumentException("Cannot be empty.", nameof(accounts));
             ITrieStore store = _trieStorePool.Get();
             try
             {

src/Nethermind/Nethermind.Synchronization/SnapSync/SnapProviderHelper.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Threading;
@@ -31,7 +32,8 @@ public static (AddRangeResult result, bool moreChildrenToRight, List<PathWithAcc
         )
         {
             // TODO: Check the accounts boundaries and sorting
-
+            if (accounts.Count == 0)
+                throw new ArgumentException("Cannot be empty.", nameof(accounts));
             ValueHash256 lastHash = accounts[^1].Path;
 
             (AddRangeResult result, List<(TrieNode, TreePath)> sortedBoundaryList, bool moreChildrenToRight) =

src/Nethermind/Nethermind.Synchronization/SnapSync/SnapSyncDownloader.cs

@@ -52,8 +52,6 @@ public async Task Dispatch(PeerInfo peerInfo, SnapSyncBatch batch, CancellationT
                         Logger.Error($"DEBUG/ERROR Error after dispatching the snap sync request. Request: {batch}", e);
                 }
             }
-
-            await Task.CompletedTask;
         }
     }
 }