Merge branch 'fakestake_correction' into 'master'

corrections to fake stake code (thanks phore team)

See merge request ProjectMerge/merge!17

src/main.cpp

@@ -3526,7 +3526,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
                 if (it == mapStakeSpent.end()) {
                     return false;
                 }
-                if (it->second <= pindexPrev->nHeight) {
+                if (it->second < pindexPrev->nHeight) {
                     return false;
                 }
             }
@@ -3538,7 +3538,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
             CBlockIndex *last = pindexPrev;
 
             // while that block is not on the main chain
-            while (!chainActive.Contains(last)) {
+            while (!chainActive.Contains(last) && last != NULL) {
                 CBlock bl;
                 ReadBlockFromDisk(bl, last);
                 // loop through every spent input from said block
@@ -3556,7 +3556,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
                 }
 
                 // go to the parent block
-                last = pindexPrev->pprev;
+                last = last->pprev;
             }
         }