[Cleanup] LoadStakeInput: no need for the previous block

src/kernel.cpp

@@ -87,19 +87,8 @@ bool CStakeKernel::CheckKernelHash(bool fSkipLog) const
  */
 
 // helper function for CheckProofOfStake and GetStakeKernelHash
-bool LoadStakeInput(const CBlock& block, const CBlockIndex* pindexPrev, std::unique_ptr<CStakeInput>& stake)
+static bool LoadStakeInput(const CBlock& block, std::unique_ptr<CStakeInput>& stake)
 {
-    // If previous index is not provided, look for it in the blockmap
-    if (!pindexPrev) {
-        BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
-        if (mi != mapBlockIndex.end() && (*mi).second) pindexPrev = (*mi).second;
-        else return error("%s : couldn't find previous block", __func__);
-    } else {
-        // check that is the actual parent block
-        if (block.hashPrevBlock != pindexPrev->GetBlockHash())
-            return error("%s : previous block mismatch", __func__);
-    }
-
     // Check that this is a PoS block
     if (!block.IsProofOfStake())
         return error("called on non PoS block");
@@ -153,7 +142,7 @@ bool CheckProofOfStake(const CBlock& block, std::string& strError, const CBlockI
     const int nHeight = pindexPrev->nHeight + 1;
     // Initialize stake input
     std::unique_ptr<CStakeInput> stakeInput;
-    if (!LoadStakeInput(block, pindexPrev, stakeInput)) {
+    if (!LoadStakeInput(block, stakeInput)) {
         strError = "stake input initialization failed";
         return false;
     }
@@ -207,7 +196,7 @@ bool GetStakeKernelHash(uint256& hashRet, const CBlock& block, const CBlockIndex
 {
     // Initialize stake input
     std::unique_ptr<CStakeInput> stakeInput;
-    if (!LoadStakeInput(block, pindexPrev, stakeInput))
+    if (!LoadStakeInput(block, stakeInput))
         return error("%s : stake input initialization failed", __func__);
 
     CStakeKernel stakeKernel(pindexPrev, stakeInput.get(), block.nBits, block.nTime);