7 files changed, 62 insertions, 7 deletions
diff --git a/src/common/notify.cpp b/src/common/notify.cpp
index cadc68ea7..c3165fb05 100644
--- a/src/common/notify.cpp
+++ b/src/common/notify.cpp
@@ -27,11 +27,15 @@
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <boost/algorithm/string.hpp>
+#include <stdarg.h>
 #include "misc_log_ex.h"
 #include "file_io_utils.h"
 #include "spawn.h"
 #include "notify.h"
 
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "notify"
+
 namespace tools
 {
 
@@ -46,15 +50,32 @@ Notify::Notify(const char *spec)
 
   boost::split(args, spec, boost::is_any_of(" "));
   CHECK_AND_ASSERT_THROW_MES(args.size() > 0, "Failed to parse spec");
+  if (strchr(spec, '\'') || strchr(spec, '\"') || strchr(spec, '\\'))
+    MWARNING("A notification spec contains a quote or backslash: note that these are handled verbatim, which may not be the intent");
   filename = args[0];
   CHECK_AND_ASSERT_THROW_MES(epee::file_io_utils::is_file_exist(filename), "File not found: " << filename);
 }
 
-int Notify::notify(const char *parameter)
+static void replace(std::vector<std::string> &v, const char *tag, const char *s)
+{
+  for (std::string &str: v)
+    boost::replace_all(str, tag, s);
+}
+
+int Notify::notify(const char *tag, const char *s, ...)
 {
   std::vector<std::string> margs = args;
-  for (std::string &s: margs)
-    boost::replace_all(s, "%s", parameter);
+
+  replace(margs, tag, s);
+
+  va_list ap;
+  va_start(ap, s);
+  while ((tag = va_arg(ap, const char*)))
+  {
+    s = va_arg(ap, const char*);
+    replace(margs, tag, s);
+  }
+  va_end(ap);
 
   return tools::spawn(filename.c_str(), margs, false);
 }
diff --git a/src/common/notify.h b/src/common/notify.h
index 81aacebb0..f813e8def 100644
--- a/src/common/notify.h
+++ b/src/common/notify.h
@@ -39,7 +39,7 @@ class Notify
 public:
   Notify(const char *spec);
 
-  int notify(const char *parameter);
+  int notify(const char *tag, const char *s, ...);
 
 private:
   std::string filename;
diff --git a/src/common/spawn.cpp b/src/common/spawn.cpp
index b2d03f62f..e03552f8c 100644
--- a/src/common/spawn.cpp
+++ b/src/common/spawn.cpp
@@ -42,6 +42,9 @@
 #include "util.h"
 #include "spawn.h"
 
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "spawn"
+
 namespace tools
 {
 
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 9f1e2a0c0..41357e72e 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -1073,6 +1073,11 @@ bool Blockchain::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::
 
   m_hardfork->reorganize_from_chain_height(split_height);
 
+  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);
+
   MGINFO_GREEN("REORGANIZE SUCCESS! on height: " << split_height << ", new blockchain size: " << m_db->height());
   return true;
 }
@@ -3701,7 +3706,7 @@ leave:
 
   std::shared_ptr<tools::Notify> block_notify = m_block_notify;
   if (block_notify)
-    block_notify->notify(epee::string_tools::pod_to_hex(id).c_str());
+    block_notify->notify("%s", epee::string_tools::pod_to_hex(id).c_str(), NULL);
 
   return true;
 }
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index 4952116ac..c742bec91 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -731,11 +731,18 @@ namespace cryptonote
     /**
      * @brief sets a block notify object to call for every new block
      *
-     * @param notify the notify object to cal at every new block
+     * @param notify the notify object to call at every new block
      */
     void set_block_notify(const std::shared_ptr<tools::Notify> &notify) { m_block_notify = notify; }
 
     /**
+     * @brief sets a reorg notify object to call for every reorg
+     *
+     * @param notify the notify object to call at every reorg
+     */
+    void set_reorg_notify(const std::shared_ptr<tools::Notify> &notify) { m_reorg_notify = notify; }
+
+    /**
      * @brief Put DB in safe sync mode
      */
     void safesyncmode(const bool onoff);
@@ -1077,6 +1084,7 @@ namespace cryptonote
     bool m_btc_valid;
 
     std::shared_ptr<tools::Notify> m_block_notify;
+    std::shared_ptr<tools::Notify> m_reorg_notify;
 
     /**
      * @brief collects the keys for all outputs being "spent" as an input
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index 48c607ff1..1513bb750 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -185,6 +185,13 @@ namespace cryptonote
   , "Prune blockchain"
   , false
   };
+  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"
+  , ""
+  };
 
   //-----------------------------------------------------------------------------------------------
   core::core(i_cryptonote_protocol* pprotocol):
@@ -300,6 +307,7 @@ namespace cryptonote
     command_line::add_arg(desc, arg_pad_transactions);
     command_line::add_arg(desc, arg_block_notify);
     command_line::add_arg(desc, arg_prune_blockchain);
+    command_line::add_arg(desc, arg_reorg_notify);
 
     miner::init_options(desc);
     BlockchainDB::init_options(desc);
@@ -582,6 +590,16 @@ namespace cryptonote
       MERROR("Failed to parse block notify spec");
     }
 
+    try
+    {
+      if (!command_line::is_arg_defaulted(vm, arg_reorg_notify))
+        m_blockchain_storage.set_reorg_notify(std::shared_ptr<tools::Notify>(new tools::Notify(command_line::get_arg(vm, arg_reorg_notify).c_str())));
+    }
+    catch (const std::exception &e)
+    {
+      MERROR("Failed to parse reorg notify spec");
+    }
+
     const std::pair<uint8_t, uint64_t> regtest_hard_forks[3] = {std::make_pair(1, 0), std::make_pair(Blockchain::get_hard_fork_heights(MAINNET).back().version, 1), std::make_pair(0, 0)};
     const cryptonote::test_options regtest_test_options = {
       regtest_hard_forks
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index e9237386d..c02d10ab4 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -2048,7 +2048,7 @@ void wallet2::process_new_transaction(const crypto::hash &txid, const cryptonote
   {
     std::shared_ptr<tools::Notify> tx_notify = m_tx_notify;
     if (tx_notify)
-      tx_notify->notify(epee::string_tools::pod_to_hex(txid).c_str());
+      tx_notify->notify("%s", epee::string_tools::pod_to_hex(txid).c_str(), NULL);
   }
 }
 //----------------------------------------------------------------------------------------------------