PPCoin: Fix GetLastBlockIndex() (ProcessBlock crash) since 8c8cd5f

diff --git a/src/main.cpp b/src/main.cpp
index 44f48fc..283a1cc 100644 (file)
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -890,7 +890,7 @@ unsigned int ComputeMinWork(unsigned int nBase, int64 nTime)
 // ppcoin: find last block index up to pindex
 const CBlockIndex* GetLastBlockIndex(const CBlockIndex* pindex, bool fProofOfStake)
 {
-    while (pindex && (pindex->IsProofOfStake() != fProofOfStake))
+    while (pindex && pindex->pprev && (pindex->IsProofOfStake() != fProofOfStake))
         pindex = pindex->pprev;
     return pindex;
 }