1 files changed, 3 insertions, 1 deletions
diff --git a/src/cryptonote_protocol/block_queue.cpp b/src/cryptonote_protocol/block_queue.cpp
index 813167400..3844d3751 100644
--- a/src/cryptonote_protocol/block_queue.cpp
+++ b/src/cryptonote_protocol/block_queue.cpp
@@ -31,6 +31,7 @@
 #include <vector>
 #include <unordered_map>
 #include <boost/uuid/nil_generator.hpp>
+#include "string_tools.h"
 #include "cryptonote_protocol_defs.h"
 #include "block_queue.h"
 
@@ -61,6 +62,7 @@ void block_queue::add_blocks(uint64_t height, std::list<cryptonote::block_comple
 
 void block_queue::add_blocks(uint64_t height, uint64_t nblocks, const boost::uuids::uuid &connection_id, boost::posix_time::ptime time)
 {
+  CHECK_AND_ASSERT_THROW_MES(nblocks > 0, "Empty span");
   boost::unique_lock<boost::recursive_mutex> lock(mutex);
   blocks.insert(span(height, nblocks, connection_id, time));
 }
@@ -383,7 +385,7 @@ float block_queue::get_speed(const boost::uuids::uuid &connection_id) const
       i->second = (i->second + span.rate) / 2;
   }
   float conn_rate = -1, best_rate = 0;
-  for (auto i: speeds)
+  for (const auto &i: speeds)
   {
     if (i.first == connection_id)
       conn_rate = i.second;