Fix AEC insert race condition

nano/node/active_transactions.cpp

@@ -327,6 +327,11 @@ void nano::active_transactions::cleanup_election (nano::unique_lock<nano::mutex>
 	debug_assert (!mutex.try_lock ());
 	debug_assert (lock_a.owns_lock ());
 
+	if (election->confirmed ())
+	{
+		debug_assert (recently_confirmed.exists (election->qualified_root));
+	}
+
 	node.stats.inc (completion_type (*election), nano::to_stat_detail (election->behavior ()));
 	// Keep track of election count by election type
 	debug_assert (count_by_behavior[election->behavior ()] > 0);

nano/node/election.cpp

@@ -35,6 +35,7 @@ nano::election::election (nano::node & node_a, std::shared_ptr<nano::block> cons
 void nano::election::confirm_once (nano::unique_lock<nano::mutex> & lock_a, nano::election_status_type type_a)
 {
 	debug_assert (lock_a.owns_lock ());
+
 	// This must be kept above the setting of election state, as dependent confirmed elections require up to date changes to election_winner_details
 	nano::unique_lock<nano::mutex> election_winners_lk{ node.active.election_winner_details_mutex };
 	if (state_m.exchange (nano::election::state_t::confirmed) != nano::election::state_t::confirmed && (node.active.election_winner_details.count (status.winner->hash ()) == 0))
@@ -48,6 +49,9 @@ void nano::election::confirm_once (nano::unique_lock<nano::mutex> & lock_a, nano
 		status.voter_count = nano::narrow_cast<decltype (status.voter_count)> (last_votes.size ());
 		status.type = type_a;
 		auto const status_l = status;
+
+		node.active.recently_confirmed.put (qualified_root, status_l.winner->hash ());
+
 		lock_a.unlock ();
 
 		node.background ([node_l = node.shared (), status_l, confirmation_action_l = confirmation_action] () {

nano/node/node.cpp

@@ -1386,7 +1386,6 @@ void nano::node::process_confirmed (nano::election_status const & status_a, uint
 	decltype (iteration_a) const num_iters = (config.block_processor_batch_max_time / network_params.node.process_confirmed_interval) * 4;
 	if (auto block_l = ledger.store.block.get (ledger.store.tx_begin_read (), hash))
 	{
-		active.recently_confirmed.put (block_l->qualified_root (), hash);
 		confirmation_height_processor.add (block_l);
 	}
 	else if (iteration_a < num_iters)