Don't use checkpoints and accept nonstd txn on -regtest

src/checkpoints.cpp

@@ -67,11 +67,24 @@ namespace Checkpoints
         300
     };
 
+    static MapCheckpoints mapCheckpointsRegtest =
+        boost::assign::map_list_of
+        ( 0, uint256("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"))
+        ;
+    static const CCheckpointData dataRegtest = {
+        &mapCheckpointsRegtest,
+        0,
+        0,
+        0
+    };
+
     const CCheckpointData &Checkpoints() {
-        if (TestNet())
+        if (Params().NetworkID() == CChainParams::TESTNET)
             return dataTestnet;
-        else
+        else if (Params().NetworkID() == CChainParams::MAIN)
             return data;
+        else
+            return dataRegtest;
     }
 
     bool CheckBlock(int nHeight, const uint256& hash)

src/main.cpp

@@ -810,9 +810,9 @@ bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fLimitFr
     if ((int64)tx.nLockTime > std::numeric_limits<int>::max())
         return error("CTxMemPool::accept() : not accepting nLockTime beyond 2038 yet");
 
-    // Rather not work on nonstandard transactions (unless -testnet)
+    // Rather not work on nonstandard transactions (unless -testnet/-regtest)
     string reason;
-    if (!TestNet() && !IsStandardTx(tx, reason))
+    if (Params().NetworkID() == CChainParams::MAIN && !IsStandardTx(tx, reason))
         return error("CTxMemPool::accept() : nonstandard transaction: %s",
                      reason.c_str());
 
@@ -888,7 +888,7 @@ bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fLimitFr
         }
 
         // Check for non-standard pay-to-script-hash in inputs
-        if (!TestNet() && !AreInputsStandard(tx, view))
+        if (Params().NetworkID() == CChainParams::MAIN && !AreInputsStandard(tx, view))
             return error("CTxMemPool::accept() : nonstandard transaction input");
 
         // Note: if you modify this code to accept non-standard transactions, then