Validation: Remove CheckBlockSignature now unneeded enableP2PKH flag.

It was only needed for the activation period, now that it's fully enforced, can be removed.
The activation time isn't needed, v5 enforcement checkpoint is ensuring that the chain cannot reorg to a time in which P2PKH stakes weren't enabled.

Github-Pull: #2295
Rebased-From: 5aa3600

src/blocksignature.cpp

@@ -40,7 +40,7 @@ bool SignBlock(CBlock& block, const CKeyStore& keystore)
     return SignBlockWithKey(block, key);
 }
 
-bool CheckBlockSignature(const CBlock& block, const bool enableP2PKH)
+bool CheckBlockSignature(const CBlock& block)
 {
     if (block.IsProofOfWork())
         return block.vchBlockSig.empty();
@@ -64,13 +64,6 @@ bool CheckBlockSignature(const CBlock& block, const bool enableP2PKH)
         if (!Solver(txout.scriptPubKey, whichType, vSolutions))
             return false;
 
-        if (!enableP2PKH) {
-            // Before v5 activation, P2PKH was always failing.
-            if (whichType == TX_PUBKEYHASH) {
-                return false;
-            }
-        }
-
         if (whichType == TX_PUBKEY) {
             valtype& vchPubKey = vSolutions[0];
             pubkey = CPubKey(vchPubKey);

src/blocksignature.h

@@ -11,6 +11,6 @@
 
 bool SignBlockWithKey(CBlock& block, const CKey& key);
 bool SignBlock(CBlock& block, const CKeyStore& keystore);
-bool CheckBlockSignature(const CBlock& block, const bool enableP2PKH);
+bool CheckBlockSignature(const CBlock& block);
 
 #endif //PIVX_BLOCKSIGNATURE_H

src/test/main_tests.cpp

@@ -72,14 +72,9 @@ CBlock CreateDummyBlockWithSignature(CKey stakingKey, BlockSignatureType type, b
     return block;
 }
 
-bool TestBlockSignaturePreEnforcementV5(const CBlock& block)
+bool TestBlockSignature(const CBlock& block)
 {
-    return CheckBlockSignature(block, false);
-}
-
-bool TestBlockSignaturePostEnforcementV5(const CBlock& block)
-{
-    return CheckBlockSignature(block, true);
+    return CheckBlockSignature(block);
 }
 
 BOOST_AUTO_TEST_CASE(block_signature_test)
@@ -89,27 +84,19 @@ BOOST_AUTO_TEST_CASE(block_signature_test)
         stakingKey.MakeNewKey(true);
         bool useInputP2PK = i % 2 == 0;
 
-        // Test P2PK block signature pre enforcement.
+        // Test P2PK block signature
         CBlock block = CreateDummyBlockWithSignature(stakingKey, BlockSignatureType::P2PK, useInputP2PK);
-        BOOST_CHECK(TestBlockSignaturePreEnforcementV5(block));
-
-        // Test P2PK block signature post enforcement
-        block = CreateDummyBlockWithSignature(stakingKey, BlockSignatureType::P2PK, useInputP2PK);
-        BOOST_CHECK(TestBlockSignaturePostEnforcementV5(block));
-
-        // Test P2PKH block signature pre enforcement ---> must fail.
-        block = CreateDummyBlockWithSignature(stakingKey, BlockSignatureType::P2PKH, useInputP2PK);
-        BOOST_CHECK(!TestBlockSignaturePreEnforcementV5(block));
+        BOOST_CHECK(TestBlockSignature(block));
 
-        // Test P2PKH block signature post enforcement
+        // Test P2PKH block signature
         block = CreateDummyBlockWithSignature(stakingKey, BlockSignatureType::P2PKH, useInputP2PK);
         if (useInputP2PK) {
             // If it's using a P2PK scriptsig as input and a P2PKH output
             // The block doesn't contain the public key to verify the sig anywhere.
             // Must fail.
-            BOOST_CHECK(!TestBlockSignaturePostEnforcementV5(block));
+            BOOST_CHECK(!TestBlockSignature(block));
         } else {
-            BOOST_CHECK(TestBlockSignaturePostEnforcementV5(block));
+            BOOST_CHECK(TestBlockSignature(block));
         }
     }
 }

src/validation.cpp

@@ -3263,15 +3263,12 @@ bool ProcessNewBlock(CValidationState& state, CNode* pfrom, const std::shared_pt
     // Preliminary checks
     int64_t nStartTime = GetTimeMillis();
     const Consensus::Params& consensus = Params().GetConsensus();
+    int newHeight = 0;
 
     // check block
     bool checked = CheckBlock(*pblock, state);
 
-    // For now, we need the tip to know whether p2pkh block signatures are accepted or not.
-    // After 5.0, this can be removed and replaced by the enforcement block time.
-    const int newHeight = chainActive.Height() + 1;
-    const bool enableP2PKH = consensus.NetworkUpgradeActive(newHeight, Consensus::UPGRADE_V5_0);
-    if (!CheckBlockSignature(*pblock, enableP2PKH))
+    if (!CheckBlockSignature(*pblock))
         return error("%s : bad proof-of-stake block signature", __func__);
 
     if (pblock->GetHash() != consensus.hashGenesisBlock && pfrom != NULL) {
@@ -3298,6 +3295,7 @@ bool ProcessNewBlock(CValidationState& state, CNode* pfrom, const std::shared_pt
         if (!ret) {
             return error("%s : AcceptBlock FAILED", __func__);
         }
+        newHeight = pindex->nHeight;
     }
 
     if (!ActivateBestChain(state, pblock, checked))