Mined money 6-months unlock window

src/cryptonote_config.h

@@ -42,6 +42,7 @@
 #define CRYPTONOTE_PUBLIC_ADDRESS_TEXTBLOB_VER          0
 #define CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_V2         288
 #define CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW            60
+#define CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_LONG       262800 // 6 months
 #define CURRENT_TRANSACTION_VERSION                     2
 #define CURRENT_BLOCK_MAJOR_VERSION                     7
 #define CURRENT_BLOCK_MINOR_VERSION                     7
@@ -196,6 +197,7 @@
 #define HF_VERSION_DETERMINISTIC_UNLOCK_TIME    16
 #define HF_VERSION_DYNAMIC_UNLOCK               16
 #define HF_VERSION_FIXED_UNLOCK                 18
+#define HF_VERSION_LONG_UNLOCK                  20
 #define HF_VERSION_BULLETPROOF_PLUS             18
 #define HF_VERSION_VIEW_TAGS                    20
 #define HF_VERSION_2021_SCALING                 20

src/cryptonote_core/blockchain.cpp

@@ -1443,7 +1443,11 @@ bool Blockchain::prevalidate_miner_transaction(const block& b, uint64_t height,
   }
   MDEBUG("Miner tx hash: " << get_transaction_hash(b.miner_tx));
 
-  if (hf_version >= HF_VERSION_FIXED_UNLOCK)
+  if (hf_version >= HF_VERSION_LONG_UNLOCK)
+  {
+    CHECK_AND_ASSERT_MES(b.miner_tx.unlock_time == height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_LONG, false, "coinbase transaction transaction has the wrong unlock time="
+      << b.miner_tx.unlock_time << ", expected " << height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_LONG);
+  } else if (hf_version >= HF_VERSION_FIXED_UNLOCK)
   {
     CHECK_AND_ASSERT_MES(b.miner_tx.unlock_time == height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_V2, false, "coinbase transaction transaction has the wrong unlock time="
       << b.miner_tx.unlock_time << ", expected " << height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_V2);

src/cryptonote_core/cryptonote_tx_utils.cpp

@@ -171,7 +171,10 @@ namespace cryptonote
       tx.version = 1;
 
     //lock
-    if (hard_fork_version >= HF_VERSION_FIXED_UNLOCK)
+    if (hard_fork_version >= HF_VERSION_LONG_UNLOCK)
+    {
+      tx.unlock_time = height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_LONG;
+    } else if (hard_fork_version >= HF_VERSION_FIXED_UNLOCK)
     {
       tx.unlock_time = height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW_V2;
     } else if (hard_fork_version < HF_VERSION_FIXED_UNLOCK && hard_fork_version >= HF_VERSION_DYNAMIC_UNLOCK)