Zero total difficulty in FindBlock (#5581)

* Fix * Fix tests
NethermindEth · Apr 20, 2023 · 14a790e · 14a790e
1 parent 44289c1
commit 14a790e
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Showing 2 changed files with 58 additions and 7 deletions.
diff --git a/src/Nethermind/Nethermind.Blockchain.Test/BlockTreeTests.cs b/src/Nethermind/Nethermind.Blockchain.Test/BlockTreeTests.cs
@@ -1308,6 +1308,34 @@ public void Cannot_insert_genesis()
             Assert.Throws<InvalidOperationException>(() => tree.Insert(new[] { genesis }));
         }
 
+        [Test, Timeout(Timeout.MaxTestTime)]
+        public void Should_set_zero_total_difficulty()
+        {
+            MemDb blocksDb = new();
+            MemDb blockInfosDb = new();
+            MemDb headersDb = new();
+            MemDb metadataDb = new();
+
+            long pivotNumber = 0L;
+
+            SyncConfig syncConfig = new();
+            syncConfig.PivotNumber = pivotNumber.ToString();
+
+            CustomSpecProvider specProvider = new(((ForkActivation)0, London.Instance));
+            specProvider.UpdateMergeTransitionInfo(null, 0);
+
+            BlockTree tree = new(blocksDb, headersDb, blockInfosDb, metadataDb,
+                new ChainLevelInfoRepository(blockInfosDb), specProvider,
+                NullBloomStorage.Instance, syncConfig, LimboLogs.Instance);
+            Block genesis = Build.A.Block.WithDifficulty(0).TestObject;
+            tree.SuggestBlock(genesis).Should().Be(AddBlockResult.Added);
+            tree.FindBlock(genesis.Hash, BlockTreeLookupOptions.None)!.TotalDifficulty.Should().Be(UInt256.Zero);
+
+            Block A = Build.A.Block.WithParent(genesis).WithDifficulty(0).TestObject;
+            tree.SuggestBlock(A).Should().Be(AddBlockResult.Added);
+            tree.FindBlock(A.Hash, BlockTreeLookupOptions.None)!.TotalDifficulty.Should().Be(UInt256.Zero);
+        }
+
         [Test, Timeout(Timeout.MaxTestTime)]
         public void Can_batch_insert_blocks()
         {

diff --git a/src/Nethermind/Nethermind.Blockchain/BlockTree.cs b/src/Nethermind/Nethermind.Blockchain/BlockTree.cs
@@ -886,8 +886,7 @@ public AddBlockResult SuggestBlock(Block block, BlockTreeSuggestOptions options
                 }
                 else
                 {
-                    if (blockInfo.TotalDifficulty != UInt256.Zero || header.IsGenesis)
-                        header.TotalDifficulty = blockInfo.TotalDifficulty;
+                    SetTotalDifficultyFromBlockInfo(header, blockInfo);
                 }
 
                 if (requiresCanonical)
@@ -1834,8 +1833,7 @@ private bool ShouldCache(long number)
                 }
                 else
                 {
-                    if (blockInfo.TotalDifficulty != UInt256.Zero || block.IsGenesis)
-                        block.Header.TotalDifficulty = blockInfo.TotalDifficulty;
+                    SetTotalDifficultyFromBlockInfo(block.Header, blockInfo);
                 }
 
                 if (requiresCanonical)
@@ -1854,6 +1852,33 @@ private bool ShouldCache(long number)
             return block;
         }
 
+        private bool IsTotalDifficultyAlwaysZero()
+        {
+            // In some Ethereum tests and possible testnets difficulty of all blocks might be zero
+            // We also checking TTD is zero to ensure that block after genesis have zero difficulty
+            return Genesis?.Difficulty == 0 && _specProvider.TerminalTotalDifficulty == 0;
+        }
+
+        private void SetTotalDifficultyFromBlockInfo(BlockHeader header, BlockInfo blockInfo)
+        {
+            if (header.IsGenesis)
+            {
+                header.TotalDifficulty = header.Difficulty;
+                return;
+            }
+
+            if (blockInfo.TotalDifficulty != UInt256.Zero)
+            {
+                header.TotalDifficulty = blockInfo.TotalDifficulty;
+                return;
+            }
+
+            if (IsTotalDifficultyAlwaysZero())
+            {
+                header.TotalDifficulty = 0;
+            }
+        }
+
         private void SetTotalDifficulty(BlockHeader header)
         {
             if (header.IsGenesis)
@@ -1863,9 +1888,7 @@ private void SetTotalDifficulty(BlockHeader header)
                 return;
             }
 
-            // In some Ethereum tests and possible testnets difficulty of all blocks might be zero
-            // We also checking TTD is zero to ensure that block after genesis have zero difficulty
-            if (Genesis!.Difficulty == 0 && _specProvider.TerminalTotalDifficulty == 0)
+            if (IsTotalDifficultyAlwaysZero())
             {
                 header.TotalDifficulty = 0;
                 if (_logger.IsTrace) _logger.Trace($"Block {header} has zero total difficulty");