ensures that the EMA has all the datapoints it needs to perform the E…

…MA caculation

src/pow.cpp

@@ -258,21 +258,27 @@ unsigned int GetNextWorkRequiredPOSV3(const CBlockIndex* pIndexLast)
  const int64_t nN = 20; // EMA period
 
  uint256 bnNew(0);
- const CBlockIndex* pIndexReading = pIndexLast;
+
+ if(pIndexLast->nHeight > nN) {
+
+ const CBlockIndex* pIndexReading = pIndexLast;
 
- for (unsigned int i = 0;
- pIndexReading && pIndexReading->nHeight && i < nN;
- i++
- ) {
- uint256 currentValue;
- currentValue.SetCompact(pIndexReading->nBits);
+  for (unsigned int i = 0;
+  pIndexReading && pIndexReading->nHeight && i < nN;
+  i++
+  ) {
+  uint256 currentValue;
+  currentValue.SetCompact(pIndexReading->nBits);
 
- bnNew = ((currentValue * nAlpha) / (nN + 1)) + ((bnNew * (nN + 1 - nAlpha)) / (nN + 1));
+  bnNew = ((currentValue * nAlpha) / (nN + 1)) + ((bnNew * (nN + 1 - nAlpha)) / (nN + 1));
 
- pIndexReading = pIndexReading->pprev;
- }
+  pIndexReading = pIndexReading->pprev;
+  }
 
- std::cout << "GetNextWorkRequiredPOSV3 nBits ema: " << GetDifficulty(bnNew.GetCompact()) << std::endl;
+ std::cout << "GetNextWorkRequiredPOSV3 nBits EMA: " << GetDifficulty(bnNew.GetCompact()) << std::endl;
+ } else {
+ bnNew.SetCompact(pIndexLast->nBits);
+ }
 
  // Retarget the difficulty based on a PID controller based function
  int64_t nActualSpacing = nHeight > 1 ? pIndexLast->GetBlockTime() - pIndexLast->pprev->GetBlockTime() : nTargetSpacing;