small ix fixes: (#1193)

- make script verification a part of IsInstantSendTxValid()
- relax nLockTime for IS txes since we don't have compatibility with 12.0 IS txes anyway now (fee is lower in 12.1)

src/instantx.cpp

@@ -85,6 +85,12 @@ bool IsInstantSendTxValid(const CTransaction& txCandidate)
     bool fMissingInputs = false;
 
     BOOST_FOREACH(const CTxOut& txout, txCandidate.vout) {
+        // InstandSend supports normal scripts and unspendable (i.e. data) scripts.
+        // TODO: Look into other script types that are normal and can be included
+        if(!txout.scriptPubKey.IsNormalPaymentScript() && !txout.scriptPubKey.IsUnspendable()) {
+            LogPrint("instantsend", "IsInstantSendTxValid -- Invalid Script %s", txCandidate.ToString());
+            return false;
+        }
         nValueOut += txout.nValue;
     }
 
@@ -126,15 +132,6 @@ bool ProcessTxLockRequest(CNode* pfrom, const CTransaction &tx)
 {
     if(!IsInstantSendTxValid(tx)) return false;
 
-    BOOST_FOREACH(const CTxOut o, tx.vout) {
-        // InstandSend supports normal scripts and unspendable scripts (used in PrivateSend collateral and Governance collateral).
-        // TODO: Look into other script types that are normal and can be included
-        if(!o.scriptPubKey.IsNormalPaymentScript() && !o.scriptPubKey.IsUnspendable()) {
-            LogPrintf("TXLOCKREQUEST -- Invalid Script %s", tx.ToString());
-            return false;
-        }
-    }
-
     int nBlockHeight = CreateTxLockCandidate(tx);
     if(!nBlockHeight) {
         // smth is not right

src/wallet/wallet.cpp

@@ -2931,8 +2931,7 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
     // now we ensure code won't be written that makes assumptions about
     // nLockTime that preclude a fix later.
 
-    // FIXME: "compatibility mode" for 12.0 IX, make it "txNew.nLockTime = chainActive.Height();" again in 12.2
-    txNew.nLockTime = fUseInstantSend ? 0 : chainActive.Height();
+    txNew.nLockTime = chainActive.Height();
 
     // Secondly occasionally randomly pick a nLockTime even further back, so
     // that transactions that are delayed after signing for whatever reason,