Add option `-permitrbf` to set transaction replacement policy

Add a configuration option `-permitrbf` to set transaction replacement policy
for the mempool.

Enabling it will enable (opt-in) RBF, disabling it will refuse all
conflicting transactions.

1 files changed, 8 insertions, 4 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 9870beecc7..8522b0d1ba 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -78,6 +78,7 @@ bool fAlerts = DEFAULT_ALERTS;
 /* If the tip is older than this (in seconds), the node is considered to be in initial block download.
  */
 int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
+bool fPermitReplacement = DEFAULT_PERMIT_REPLACEMENT;
 
 /** Fees smaller than this (in satoshi) are considered zero fee (for relaying, mining and transaction creation) */
 CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
@@ -868,12 +869,15 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState &state, const C
                 // unconfirmed ancestors anyway; doing otherwise is hopelessly
                 // insecure.
                 bool fReplacementOptOut = true;
-                BOOST_FOREACH(const CTxIn &txin, ptxConflicting->vin)
+                if (fPermitReplacement)
                 {
-                    if (txin.nSequence < std::numeric_limits<unsigned int>::max()-1)
+                    BOOST_FOREACH(const CTxIn &txin, ptxConflicting->vin)
                     {
-                        fReplacementOptOut = false;
-                        break;
+                        if (txin.nSequence < std::numeric_limits<unsigned int>::max()-1)
+                        {
+                            fReplacementOptOut = false;
+                            break;
+                        }
                     }
                 }
                 if (fReplacementOptOut)