From 0747d4afe46878b357fa08f43376c56f505e30c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Wo=CC=81jcik?=
 <3044353+pwojcikdev@users.noreply.github.com>
Date: Sat, 12 Oct 2024 11:59:17 +0200
Subject: [PATCH] Handle rollbacks when cementing

---
 nano/node/confirming_set.cpp | 8 ++++++++
 nano/secure/ledger.cpp       | 5 ++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/nano/node/confirming_set.cpp b/nano/node/confirming_set.cpp
index c499e350..da342a4e 100644
--- a/nano/node/confirming_set.cpp
+++ b/nano/node/confirming_set.cpp
@@ -1,6 +1,7 @@
 #include <nano/lib/thread_roles.hpp>
 #include <nano/node/confirming_set.hpp>
 #include <nano/secure/ledger.hpp>
+#include <nano/secure/ledger_set_any.hpp>
 #include <nano/secure/ledger_set_confirmed.hpp>
 #include <nano/store/component.hpp>
 #include <nano/store/write_queue.hpp>
@@ -180,6 +181,13 @@ void nano::confirming_set::run_batch (std::unique_lock<std::mutex> & lock)
 
 				stats.inc (nano::stat::type::confirming_set, nano::stat::detail::cementing);
 
+				// The block might be rolled back before it's fully cemented
+				if (!ledger.any.block_exists (transaction, hash))
+				{
+					stats.inc (nano::stat::type::confirming_set, nano::stat::detail::missing_block);
+					break;
+				}
+
 				auto added = ledger.confirm (transaction, hash, config.max_blocks);
 				if (!added.empty ())
 				{
diff --git a/nano/secure/ledger.cpp b/nano/secure/ledger.cpp
index efe7c5ad..cba173a6 100644
--- a/nano/secure/ledger.cpp
+++ b/nano/secure/ledger.cpp
@@ -865,7 +865,10 @@ std::deque<std::shared_ptr<nano::block>> nano::ledger::confirm (secure::write_tr
 		bool refreshed = transaction.refresh_if_needed ();
 		if (refreshed)
 		{
-			release_assert (any.block_exists (transaction, target_hash), "block was rolled back during cementing");
+			if (!any.block_exists (transaction, target_hash))
+			{
+				break; // Block was rolled back during cementing
+			}
 		}
 
 		// Early return might leave parts of the dependency tree unconfirmed