Update mn vote time for remote masternodes

 - call UpdateWatchdogVoteTime in CMasternodeMan::ProcessMessage
 - deserialize masternodeping from the previous version archive without exception
 - add ability to set time in UpdateWatchdogVoteTime
 - set nTimeLastWatchdogVote to masternode ping sigTime if sentinel is actual
 - bump CMasternodeMan::SERIALIZATION_VERSION_STRING

Author: Sergey

src/masternode.cpp

@@ -911,10 +911,13 @@ void CMasternode::RemoveGovernanceObject(uint256 nGovernanceObjectHash)
     mapGovernanceObjectsVotedOn.erase(it);
 }
 
-void CMasternode::UpdateWatchdogVoteTime()
+void CMasternode::UpdateWatchdogVoteTime(uint64_t t)
 {
     LOCK(cs);
-    nTimeLastWatchdogVote = GetTime();
+    if(t == 0)
+        nTimeLastWatchdogVote = GetTime();
+    else
+        nTimeLastWatchdogVote = t;
 }
 
 /**

src/masternode.h

@@ -23,6 +23,7 @@ static const int MASTERNODE_WATCHDOG_MAX_SECONDS        = 120 * 60;
 static const int MASTERNODE_NEW_START_REQUIRED_SECONDS  = 180 * 60;
 
 static const int MASTERNODE_POSE_BAN_MAX_SCORE          = 5;
+
 //
 // The Masternode Ping Class : Contains a different serialize method for sending pings from masternodes throughout the network
 //
@@ -57,6 +58,8 @@ class CMasternodePing
         READWRITE(blockHash);
         READWRITE(sigTime);
         READWRITE(vchSig);
+        if(ser_action.ForRead() && (s.size() == 0))
+            return;
         READWRITE(sentinelIsActual);
         READWRITE(sentinelVersion);
     }
@@ -326,7 +329,7 @@ class CMasternode
 
     void RemoveGovernanceObject(uint256 nGovernanceObjectHash);
 
-    void UpdateWatchdogVoteTime();
+    void UpdateWatchdogVoteTime(uint64_t t = 0);
 
     CMasternode& operator=(CMasternode from)
     {

src/masternodeman.cpp

@@ -16,7 +16,7 @@
 /** Masternode manager */
 CMasternodeMan mnodeman;
 
-const std::string CMasternodeMan::SERIALIZATION_VERSION_STRING = "CMasternodeMan-Version-4";
+const std::string CMasternodeMan::SERIALIZATION_VERSION_STRING = "CMasternodeMan-Version-5";
 
 struct CompareLastPaidBlock
 {
@@ -849,6 +849,12 @@ void CMasternodeMan::ProcessMessage(CNode* pfrom, std::string& strCommand, CData
         // see if we have this Masternode
         CMasternode* pmn = mnodeman.Find(mnp.vin);
 
+        // if masternode uses sentinel ping instead of watchdog
+        // we shoud update nTimeLastWatchdogVote here if sentinel
+        // ping flag is actual
+        if(pmn && mnp.sentinelIsActual)
+            pmn->UpdateWatchdogVoteTime(mnp.sigTime);
+
         // too late, new MNANNOUNCE is required
         if(pmn && pmn->IsNewStartRequired()) return;
 
@@ -1649,7 +1655,7 @@ void CMasternodeMan::SetMasternodeLastPing(const CTxIn& vin, const CMasternodePi
     // we shoud update nTimeLastWatchdogVote here if sentinel
     // ping flag is actual
     if(mnp.sentinelIsActual)
-        pMN->UpdateWatchdogVoteTime();
+        pMN->UpdateWatchdogVoteTime(mnp.sigTime);
     mapSeenMasternodePing.insert(std::make_pair(mnp.GetHash(), mnp));
 
     CMasternodeBroadcast mnb(*pMN);