Check if a block can still fit before sending out a vote and if not, terminate the election.

rai/node/node.cpp

@@ -3472,8 +3472,15 @@ void rai::election::compute_rep_votes (MDB_txn * transaction_a)
 
 void rai::election::broadcast_winner (MDB_txn * transaction_a)
 {
-	compute_rep_votes (transaction_a);
-	node.network.republish_block (transaction_a, status.winner);
+	if (node.ledger.could_fit (transaction_a, *status.winner))
+	{
+		compute_rep_votes (transaction);
+		node.network.republish_block (transaction, status.winner);
+	}
+	else
+	{
+		abort ();
+	}
 }
 
 void rai::election::confirm_once (MDB_txn * transaction_a)
@@ -3490,6 +3497,11 @@ void rai::election::confirm_once (MDB_txn * transaction_a)
 	}
 }
 
+void rai::election::abort ()
+{
+	confirmed = true;
+}
+
 bool rai::election::have_quorum (rai::tally_t const & tally_a)
 {
 	auto i (tally_a.begin ());
@@ -3605,7 +3617,7 @@ void rai::active_transactions::announce_votes ()
 	for (auto i (roots.begin ()), n (roots.end ()); i != n; ++i)
 	{
 		auto election_l (i->election);
-		if ((!node.store.root_exists (transaction, election_l->votes.id) || election_l->confirmed) && i->announcements >= announcement_min - 1)
+		if (election_l->confirmed && i->announcements >= announcement_min - 1)
 		{
 			if (election_l->confirmed)
 			{

rai/node/node.hpp

@@ -55,6 +55,7 @@ class election : public std::enable_shared_from_this<rai::election>
 {
 	std::function<void(std::shared_ptr<rai::block>)> confirmation_action;
 	void confirm_once (MDB_txn *);
+	void abort ();
 
 public:
 	election (rai::node &, std::shared_ptr<rai::block>, std::function<void(std::shared_ptr<rai::block>)> const &);

rai/secure/ledger.cpp

@@ -891,6 +891,52 @@ void rai::ledger::dump_account_chain (rai::account const & account_a)
 	}
 }
 
+class block_fit_visitor : public rai::block_visitor
+{
+public:
+	block_fit_visitor(rai::ledger & ledger_a, MDB_txn * transaction_a) :
+	ledger (ledger_a),
+	transaction (transaction_a),
+	result (false)
+	{
+	}
+	void send_block (rai::send_block const & block_a) override
+	{
+		result = ledger.store.block_exists(transaction, block_a.previous());
+	}
+	void receive_block (rai::receive_block const & block_a) override
+	{
+		result = ledger.store.block_exists(transaction, block_a.previous());
+		result &= ledger.store.block_exists(transaction, block_a.source());
+	}
+	void open_block (rai::open_block const & block_a) override
+	{
+		result = ledger.store.block_exists(transaction, block_a.source ());
+	}
+	void change_block (rai::change_block const & block_a) override
+	{
+		result = ledger.store.block_exists(transaction, block_a.previous());
+	}
+	void state_block (rai::state_block const & block_a) override
+	{
+		result = block_a.previous().is_zero() || ledger.store.block_exists (transaction, block_a.previous());
+		if (result && !ledger.is_send (transaction, block_a))
+		{
+			result &= ledger.store.block_exists(transaction, block_a.hashables.link);
+		}
+	}
+	rai::ledger & ledger;
+	MDB_txn * transaction;
+	bool result;
+};
+
+bool rai::ledger::could_fit (MDB_txn * transaction_a, rai::block const & block_a)
+{
+	block_fit_visitor visitor (*this, transaction_a);
+	block_a.visit (visitor);
+	return visitor.result;
+}
+
 void rai::ledger::checksum_update (MDB_txn * transaction_a, rai::block_hash const & hash_a)
 {
 	rai::checksum value;

rai/secure/ledger.hpp

@@ -45,6 +45,7 @@ public:
 	void checksum_update (MDB_txn *, rai::block_hash const &);
 	rai::checksum checksum (MDB_txn *, rai::account const &, rai::account const &);
 	void dump_account_chain (rai::account const &);
+	bool could_fit (MDB_txn *, rai::block const &);
 	static rai::uint128_t const unit;
 	rai::block_store & store;
 	rai::stat & stats;