Merge branch 'beta' into mergemaster

# Conflicts:
#	src/main.cpp

src/cc/disputepayout.cpp

@@ -0,0 +1,84 @@
+#include <cryptoconditions.h>
+
+#include "hash.h"
+#include "chain.h"
+#include "version.h"
+#include "script/cc.h"
+#include "cc/eval.h"
+#include "cc/betprotocol.h"
+#include "primitives/transaction.h"
+
+
+/*
+ * Crypto-Condition EVAL method that resolves a dispute of a session
+ *
+ * IN: vm - AppVM virtual machine to verify states
+ * IN: params - condition params
+ * IN: disputeTx - transaction attempting to resolve dispute
+ * IN: nIn  - index of input of dispute tx
+ *
+ * disputeTx: attempt to resolve a dispute
+ *
+ *   in  0:      Spends Session TX first output, reveals DisputeHeader
+ *   out 0:      OP_RETURN hash of payouts
+ */
+bool Eval::DisputePayout(AppVM &vm, std::vector<uint8_t> params, const CTransaction &disputeTx, unsigned int nIn)
+{
+    if (disputeTx.vout.size() == 0) return Invalid("no-vouts");
+
+    // get payouts hash
+    uint256 payoutHash;
+    if (!GetOpReturnHash(disputeTx.vout[0].scriptPubKey, payoutHash))
+        return Invalid("invalid-payout-hash");
+
+    // load params
+    uint16_t waitBlocks;
+    std::vector<uint8_t> vmParams;
+    if (!E_UNMARSHAL(params, ss >> VARINT(waitBlocks); ss >> vmParams))
+        return Invalid("malformed-params");
+
+    // ensure that enough time has passed
+    {
+        CTransaction sessionTx;
+        CBlockIndex sessionBlock;
+        
+        // if unconformed its too soon
+        if (!GetTxConfirmed(disputeTx.vin[0].prevout.hash, sessionTx, sessionBlock))
+            return Error("couldnt-get-parent");
+
+        if (GetCurrentHeight() < sessionBlock.nHeight + waitBlocks)
+            return Invalid("dispute-too-soon");  // Not yet
+    }
+
+    // get spends
+    std::vector<CTransaction> spends;
+    if (!GetSpendsConfirmed(disputeTx.vin[0].prevout.hash, spends))
+        return Error("couldnt-get-spends");
+
+    // verify result from VM
+    int maxLength = -1;
+    uint256 bestPayout;
+    for (int i=1; i<spends.size(); i++)
+    {
+        std::vector<unsigned char> vmState;
+        if (spends[i].vout.size() == 0) continue;
+        if (!GetOpReturnData(spends[i].vout[0].scriptPubKey, vmState)) continue;
+        auto out = vm.evaluate(vmParams, vmState);
+        uint256 resultHash = SerializeHash(out.second);
+        if (out.first > maxLength) {
+            maxLength = out.first;
+            bestPayout = resultHash;
+        }
+        // The below means that if for any reason there is a draw, the first dispute wins
+        else if (out.first == maxLength) {
+            if (bestPayout != payoutHash) {
+                fprintf(stderr, "WARNING: VM has multiple solutions of same length\n");
+                bestPayout = resultHash;
+            }
+        }
+    }
+
+    if (maxLength == -1) return Invalid("no-evidence");
+
+    return bestPayout == payoutHash ? Valid() : Invalid("wrong-payout");
+}