blockchain: include number of discarded blocks in --reorg-notify

src/cryptonote_core/blockchain.cpp

@@ -1019,6 +1019,7 @@ bool Blockchain::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::
   }
 
   // if we're to keep the disconnected blocks, add them as alternates
+  const size_t discarded_blocks = disconnected_chain.size();
   if(!discard_disconnected_chain)
   {
     //pushing old chain as alternative chain
@@ -1046,7 +1047,7 @@ bool Blockchain::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::
   std::shared_ptr<tools::Notify> reorg_notify = m_reorg_notify;
   if (reorg_notify)
     reorg_notify->notify("%s", std::to_string(split_height).c_str(), "%h", std::to_string(m_db->height()).c_str(),
-        "%n", std::to_string(m_db->height() - split_height).c_str(), NULL);
+        "%n", std::to_string(m_db->height() - split_height).c_str(), "%d", std::to_string(discarded_blocks).c_str(), NULL);
 
   MGINFO_GREEN("REORGANIZE SUCCESS! on height: " << split_height << ", new blockchain size: " << m_db->height());
   return true;

src/cryptonote_core/cryptonote_core.cpp

@@ -176,8 +176,9 @@ namespace cryptonote
   static const command_line::arg_descriptor<std::string> arg_reorg_notify = {
     "reorg-notify"
   , "Run a program for each reorg, '%s' will be replaced by the split height, "
-    "'%h' will be replaced by the new blockchain height, and '%n' will be "
-    "replaced by the number of new blocks in the new chain"
+    "'%h' will be replaced by the new blockchain height, '%n' will be "
+    "replaced by the number of new blocks in the new chain, and '%d' will be "
+    "replaced by the number of blocks discarded from the old chain"
   , ""
   };
   static const command_line::arg_descriptor<std::string> arg_block_rate_notify = {