blockchain: fix bitflipping test with quantized block rewards

Block reward may now be less than the full amount allowed.
This was breaking the bitflipping test.
We now keep track of whether a block which was accepted by the core
has a lower than allowed block reward, and allow this in the test.

3 files changed, 6 insertions, 2 deletions

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 6bdbdf4cd..a178d1203 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -941,13 +941,14 @@ bool Blockchain::prevalidate_miner_transaction(const block& b, uint64_t height)
 }
 //------------------------------------------------------------------
 // This function validates the miner transaction reward
-bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins)
+bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins, bool &partial_block_reward)
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   //validate reward
   uint64_t money_in_use = 0;
   BOOST_FOREACH(auto& o, b.miner_tx.vout)
     money_in_use += o.amount;
+  partial_block_reward = false;
 
   std::vector<size_t> last_blocks_sizes;
   get_last_n_blocks_sizes(last_blocks_sizes, CRYPTONOTE_REWARD_BLOCKS_WINDOW);
@@ -977,6 +978,8 @@ bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_bl
     // emission. This modifies the emission curve very slightly.
     CHECK_AND_ASSERT_MES(money_in_use - fee <= base_reward, false, "base reward calculation bug");
     base_reward = money_in_use - fee;
+    if(base_reward + fee != money_in_use)
+      partial_block_reward = true;
   }
   return true;
 }
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index 1efc4e394..381236dba 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -253,7 +253,7 @@ namespace cryptonote
     bool handle_alternative_block(const block& b, const crypto::hash& id, block_verification_context& bvc);
     difficulty_type get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei) const;
     bool prevalidate_miner_transaction(const block& b, uint64_t height);
-    bool validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins);
+    bool validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins, bool &partial_block_reward);
     bool validate_transaction(const block& b, uint64_t height, const transaction& tx);
     bool rollback_blockchain_switching(std::list<block>& original_chain, uint64_t rollback_height);
     bool add_transaction_from_block(const transaction& tx, const crypto::hash& tx_id, const crypto::hash& bl_id, uint64_t bl_height);
diff --git a/src/cryptonote_core/verification_context.h b/src/cryptonote_core/verification_context.h
index c467d35f3..9766b217e 100644
--- a/src/cryptonote_core/verification_context.h
+++ b/src/cryptonote_core/verification_context.h
@@ -48,5 +48,6 @@ namespace cryptonote
     bool m_verifivation_failed; //bad block, should drop connection
     bool m_marked_as_orphaned;
     bool m_already_exists;
+    bool m_partial_block_reward;
   };
 }