Add Overwinter to upgrade list

src/chainparams.cpp

@@ -94,6 +94,8 @@ public:
             Consensus::NetworkUpgrade::ALWAYS_ACTIVE;
         consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight =
+            Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
         /**
          * The message start string should be awesome! ⓩ❤
@@ -250,6 +252,8 @@ public:
             Consensus::NetworkUpgrade::ALWAYS_ACTIVE;
         consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight =
+            Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
         pchMessageStart[0] = 0xfa;
         pchMessageStart[1] = 0x1a;
@@ -355,6 +359,8 @@ public:
             Consensus::NetworkUpgrade::ALWAYS_ACTIVE;
         consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight =
+            Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
         pchMessageStart[0] = 0xaa;
         pchMessageStart[1] = 0xe8;

src/consensus/params.h

@@ -22,6 +22,7 @@ enum UpgradeIndex {
     // Sprout must be first
     BASE_SPROUT,
     UPGRADE_TESTDUMMY,
+    UPGRADE_OVERWINTER,
     // NOTE: Also add new upgrades to NetworkUpgradeInfo in upgrades.cpp
     MAX_NETWORK_UPGRADES
 };

src/consensus/upgrades.cpp

@@ -18,6 +18,11 @@ const struct NUInfo NetworkUpgradeInfo[Consensus::MAX_NETWORK_UPGRADES] = {
         /*.nBranchId =*/ 0x74736554,
         /*.strName =*/ "Test dummy",
         /*.strInfo =*/ "Test dummy info",
+    },
+    {
+        /*.nBranchId =*/ 0x5ba81b19,
+        /*.strName =*/ "Overwinter",
+        /*.strInfo =*/ "TBD",
     }
 };