Merge #885: [Backport] 3.2.2 backports

85ee5f2 Fix incorrect last checkpoint timestamp (Fuzzbawls)
bd4f505 [Net] Add additional checkpoints (Fuzzbawls)
a5c4b62 [Net] AcceptBlock, first prev block loaded from disk. (furszy)
a36360b [Net] Valid blocks from forks badly rejected due an invalid view of the available utxo set for forked chains + split height going one block further than what should be. (furszy)

Tree-SHA512: cd71b22893c01ae80faee9dbd737095718a4ffbedf6d94f984c0878e5e48513acf4822626dbc10ed624f5f2a5fd627dca7435d1cafc53cb639f71ab33f301fef

src/chainparams.cpp

@@ -69,11 +69,13 @@ static Checkpoints::MapCheckpoints mapCheckpoints =
     (908000, uint256("202708f8c289b676fceb832a079ff6b308a28608339acbf7584de533619d014d"))
     (1142400, uint256("98aff9d605bf123247f98b1e3a02567eb5799d208d78ec30fb89737b1c1f79c5"))
     (1679090, uint256("f747ce055ba1b12e1f2e842bd480bc647210799359cb2e553ab292065e3419d6")) //!< First block with a "wrapped" serial spend
-    (1686229, uint256("bb42bf1e886a7c23474634c90893dd3d68a6ccbfea4ac92a98da5cad0c6a6cb7")); //!< Last block in the "wrapped" serial attack range
+    (1686229, uint256("bb42bf1e886a7c23474634c90893dd3d68a6ccbfea4ac92a98da5cad0c6a6cb7")) //!< Last block in the "wrapped" serial attack range
+    (1778954, uint256("0d3241268264a2908d6babf00d9cd1ffb83d93d7bb4e428820127fe227c2029c")) //!< Network split here
+    (1788528, uint256("ea9243ff8fc079fdd7a04f11fac415de4d98e1bb0dc38db6f79f8f8bbfdbe496")); //!< Network split here
 static const Checkpoints::CCheckpointData data = {
     &mapCheckpoints,
-    1551924791, // * UNIX timestamp of last checkpoint block
-    4036872,    // * total number of transactions between genesis and last checkpoint
+    1556924938, // * UNIX timestamp of last checkpoint block
+    4271692,    // * total number of transactions between genesis and last checkpoint
                 //   (the tx=... number in the SetBestChain debug.log lines)
     2000        // * estimated number of transactions per day after checkpoint
 };

src/main.cpp

@@ -4693,47 +4693,53 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
             // Start at the block we're adding on to
             CBlockIndex *prev = pindexPrev;
 
-            int readBlock = 0;
-            vector<CBigNum> vBlockSerials;
             CBlock bl;
+            if (!ReadBlockFromDisk(bl, prev))
+                return error("%s: previous block %s not on disk", __func__, prev->GetBlockHash().GetHex());
+
+            vector<CBigNum> vBlockSerials;
+            int readBlock = 0;
             // Go backwards on the forked chain up to the split
-            do {
+            while (!chainActive.Contains(prev)) {
+
+                // Increase amount of read blocks
+                readBlock++;
                 // Check if the forked chain is longer than the max reorg limit
-                if(readBlock == Params().MaxReorganizationDepth()){
+                if (readBlock == Params().MaxReorganizationDepth()) {
                     // TODO: Remove this chain from disk.
                     return error("%s: forked chain longer than maximum reorg limit", __func__);
                 }
 
-                if(!ReadBlockFromDisk(bl, prev))
-                    // Previous block not on disk
-                    return error("%s: previous block %s not on disk", __func__, prev->GetBlockHash().GetHex());
-                // Increase amount of read blocks
-                readBlock++;
                 // Loop through every input from said block
-                for (const CTransaction& t : bl.vtx) {
-                    for (const CTxIn& in: t.vin) {
+                for (const CTransaction &t : bl.vtx) {
+                    for (const CTxIn &in: t.vin) {
                         // Loop through every input of the staking tx
-                        for (const CTxIn& stakeIn : pivInputs) {
+                        for (const CTxIn &stakeIn : pivInputs) {
                             // if it's already spent
 
                             // First regular staking check
-                            if(hasPIVInputs) {
+                            if (hasPIVInputs) {
                                 if (stakeIn.prevout == in.prevout) {
-                                    return state.DoS(100, error("%s: input already spent on a previous block", __func__));
+                                    return state.DoS(100, error("%s: input already spent on a previous block",
+                                                                __func__));
                                 }
 
                                 // Second, if there is zPoS staking then store the serials for later check
-                                if(in.scriptSig.IsZerocoinSpend()){
+                                if (in.scriptSig.IsZerocoinSpend()) {
                                     vBlockSerials.push_back(TxInToZerocoinSpend(in).getCoinSerialNumber());
                                 }
                             }
                         }
                     }
                 }
 
+                // Prev block
                 prev = prev->pprev;
+                if (!ReadBlockFromDisk(bl, prev))
+                    // Previous block not on disk
+                    return error("%s: previous block %s not on disk", __func__, prev->GetBlockHash().GetHex());
 
-            } while (!chainActive.Contains(prev));
+            }
 
             // Split height
             splitHeight = prev->nHeight;
@@ -4795,9 +4801,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
                     return error("%s: coin stake inputs not available on main chain, received height %d vs current %d", __func__, nHeight, chainActive.Height());
                 }
                 if(coin && !coin->IsAvailable(in.prevout.n)){
-                    // If this is not available get the height of the spent and validate it with the forked height
-                    // Check if this occurred before the chain split
-                    if(!(isBlockFromFork && coin->nHeight > splitHeight)){
+                    if(!isBlockFromFork){
                         // Coins not available
                         return error("%s: coin stake inputs already spent in main chain", __func__);
                     }