get_blockchain_top now returns void

It was always returning true, and could not be foreseen to
usefully return errors in the future. This silences CID 162652
as well as saves some checking code in a few places.

src/cryptonote_core/cryptonote_core.cpp

@@ -211,10 +211,9 @@ namespace cryptonote
     return m_blockchain_storage.get_current_blockchain_height();
   }
   //-----------------------------------------------------------------------------------------------
-  bool core::get_blockchain_top(uint64_t& height, crypto::hash& top_id) const
+  void core::get_blockchain_top(uint64_t& height, crypto::hash& top_id) const
   {
     top_id = m_blockchain_storage.get_tail_id(height);
-    return true;
   }
   //-----------------------------------------------------------------------------------------------
   bool core::get_blocks(uint64_t start_offset, size_t count, std::list<std::pair<cryptonote::blobdata,block>>& blocks, std::list<cryptonote::blobdata>& txs) const

src/cryptonote_core/cryptonote_core.h

@@ -299,10 +299,8 @@ namespace cryptonote
       *
       * @param height return-by-reference height of the block
       * @param top_id return-by-reference hash of the block
-      *
-      * @return true
       */
-     bool get_blockchain_top(uint64_t& height, crypto::hash& top_id) const;
+     void get_blockchain_top(uint64_t& height, crypto::hash& top_id) const;
 
      /**
       * @copydoc Blockchain::get_blocks(uint64_t, size_t, std::list<std::pair<cryptonote::blobdata,block>>&, std::list<transaction>&) const

src/rpc/core_rpc_server.cpp

@@ -128,11 +128,7 @@ namespace cryptonote
   {
     CHECK_CORE_BUSY();
     crypto::hash top_hash;
-    if (!m_core.get_blockchain_top(res.height, top_hash))
-    {
-      res.status = "Failed";
-      return false;
-    }
+    m_core.get_blockchain_top(res.height, top_hash);
     ++res.height; // turn top block height into blockchain height
     res.top_block_hash = string_tools::pod_to_hex(top_hash);
     res.target_height = m_core.get_target_blockchain_height();
@@ -1061,13 +1057,7 @@ namespace cryptonote
     }
     uint64_t last_block_height;
     crypto::hash last_block_hash;
-    bool have_last_block_hash = m_core.get_blockchain_top(last_block_height, last_block_hash);
-    if (!have_last_block_hash)
-    {
-      error_resp.code = CORE_RPC_ERROR_CODE_INTERNAL_ERROR;
-      error_resp.message = "Internal error: can't get last block hash.";
-      return false;
-    }
+    m_core.get_blockchain_top(last_block_height, last_block_hash);
     block last_block;
     bool have_last_block = m_core.get_block_by_hash(last_block_hash, last_block);
     if (!have_last_block)
@@ -1300,11 +1290,7 @@ namespace cryptonote
     }
 
     crypto::hash top_hash;
-    if (!m_core.get_blockchain_top(res.height, top_hash))
-    {
-      res.status = "Failed";
-      return false;
-    }
+    m_core.get_blockchain_top(res.height, top_hash);
     ++res.height; // turn top block height into blockchain height
     res.top_block_hash = string_tools::pod_to_hex(top_hash);
     res.target_height = m_core.get_target_blockchain_height();
@@ -1716,11 +1702,7 @@ namespace cryptonote
     }
 
     crypto::hash top_hash;
-    if (!m_core.get_blockchain_top(res.height, top_hash))
-    {
-      res.status = "Failed";
-      return false;
-    }
+    m_core.get_blockchain_top(res.height, top_hash);
     ++res.height; // turn top block height into blockchain height
     res.target_height = m_core.get_target_blockchain_height();
 

tests/core_proxy/core_proxy.cpp

@@ -229,10 +229,9 @@ bool tests::proxy_core::get_short_chain_history(std::list<crypto::hash>& ids) {
     return true;
 }
 
-bool tests::proxy_core::get_blockchain_top(uint64_t& height, crypto::hash& top_id) {
+void tests::proxy_core::get_blockchain_top(uint64_t& height, crypto::hash& top_id) {
     height = 0;
     top_id = get_block_hash(m_genesis);
-    return true;
 }
 
 bool tests::proxy_core::init(const boost::program_options::variables_map& /*vm*/) {

tests/core_proxy/core_proxy.h

@@ -74,7 +74,7 @@ namespace tests
     bool get_short_chain_history(std::list<crypto::hash>& ids);
     bool get_stat_info(cryptonote::core_stat_info& st_inf){return true;}
     bool have_block(const crypto::hash& id);
-    bool get_blockchain_top(uint64_t& height, crypto::hash& top_id);
+    void get_blockchain_top(uint64_t& height, crypto::hash& top_id);
     bool handle_incoming_tx(const cryptonote::blobdata& tx_blob, cryptonote::tx_verification_context& tvc, bool keeped_by_block, bool relayed, bool do_not_relay);
     bool handle_incoming_txs(const std::list<cryptonote::blobdata>& tx_blobs, std::vector<cryptonote::tx_verification_context>& tvc, bool keeped_by_block, bool relayed, bool do_not_relay);
     bool handle_incoming_block(const cryptonote::blobdata& block_blob, cryptonote::block_verification_context& bvc, bool update_miner_blocktemplate = true);

tests/unit_tests/ban.cpp

@@ -51,7 +51,7 @@ public:
   bool get_short_chain_history(std::list<crypto::hash>& ids) const { return true; }
   bool get_stat_info(cryptonote::core_stat_info& st_inf) const {return true;}
   bool have_block(const crypto::hash& id) const {return true;}
-  bool get_blockchain_top(uint64_t& height, crypto::hash& top_id)const{height=0;top_id=cryptonote::null_hash;return true;}
+  void get_blockchain_top(uint64_t& height, crypto::hash& top_id)const{height=0;top_id=cryptonote::null_hash;}
   bool handle_incoming_tx(const cryptonote::blobdata& tx_blob, cryptonote::tx_verification_context& tvc, bool keeped_by_block, bool relayed, bool do_not_relay) { return true; }
   bool handle_incoming_txs(const std::list<cryptonote::blobdata>& tx_blob, std::vector<cryptonote::tx_verification_context>& tvc, bool keeped_by_block, bool relayed, bool do_not_relay) { return true; }
   bool handle_incoming_block(const cryptonote::blobdata& block_blob, cryptonote::block_verification_context& bvc, bool update_miner_blocktemplate = true) { return true; }