RBF is not disabled by default anymore

But it's not enabled by default either: the developer is forced to
make a decision if he wants to avoid the compile-time warnings.

This way we avoid the potential problems that could have been caused
by simply switching the default to be RFB-enabled, as discussed
originally here: MetacoSA#355

Author: knocte

NBitcoin/ConsensusFactory.cs

@@ -120,13 +120,27 @@ public virtual TxOut CreateTxOut()
 #pragma warning restore CS0618 // Type or member is obsolete
 		}
 
+		protected virtual TransactionBuilder CreateTransactionBuilderCore(bool RBF)
+		{
+			return new TransactionBuilder(RBF);
+		}
+
+		[Obsolete("Use CreateTransactionBuilder(bool RBF)")]
 		protected virtual TransactionBuilder CreateTransactionBuilderCore()
 		{
 #pragma warning disable CS0618 // Type or member is obsolete
 			return new TransactionBuilder();
 #pragma warning restore CS0618 // Type or member is obsolete
 		}
 
+		public TransactionBuilder CreateTransactionBuilder(bool RBF)
+		{
+			var builder = CreateTransactionBuilderCore(RBF);
+			builder.SetConsensusFactory(this);
+			return builder;
+		}
+
+		[Obsolete("Use CreateTransactionBuilder(bool RBF)")]
 		public TransactionBuilder CreateTransactionBuilder()
 		{
 #pragma warning disable CS0618 // Type or member is obsolete

NBitcoin/Network.cs

@@ -2513,7 +2513,13 @@ internal NetworkStringParser NetworkStringParser
 			get;
 			set;
 		} = new NetworkStringParser();
+
+		public TransactionBuilder CreateTransactionBuilder(bool RBF)
+		{
+			return consensus.ConsensusFactory.CreateTransactionBuilder(RBF);
+		}
 
+		[Obsolete("Use CreateTransactionBuilder(bool RBF)")]
 		public TransactionBuilder CreateTransactionBuilder()
 		{
 			return consensus.ConsensusFactory.CreateTransactionBuilder();

NBitcoin/TransactionBuilder.cs

@@ -555,17 +555,22 @@ internal BuilderGroup CurrentGroup
 				return _CurrentGroup;
 			}
 		}
-		[Obsolete("Use Network.CreateTransactionBuilder() or ConsensusFactory.CreateTransactionBuilder() instead")]
-		public TransactionBuilder()
+
+		internal TransactionBuilder(bool RBF)
 		{
 			ShuffleRandom = new Random();
 			CoinSelector = new DefaultCoinSelector(ShuffleRandom);
 			StandardTransactionPolicy = new StandardTransactionPolicy();
 			DustPrevention = true;
-			OptInRBF = false;
+			this.RBF = RBF;
 			InitExtensions();
 		}
 
+		[Obsolete("Use Network.CreateTransactionBuilder() or ConsensusFactory.CreateTransactionBuilder() instead")]
+		public TransactionBuilder() : this(false)
+		{
+		}
+
 		private void InitExtensions()
 		{
 			Extensions.Add(new P2PKHBuilderExtension());
@@ -602,17 +607,18 @@ public bool DustPrevention
 		{
 			get;
 			set;
-		}
+		}
 
+		[Obsolete("Use Network.CreateTransactionBuilder(RBF) or ConsensusFactory.CreateTransactionBuilder(RBF) instead")]
 		/// <summary>
-		/// If true, it will signal the transaction replaceability in every input. (Default: false)
+		/// If true, it will signal the transaction replaceability in every input.
 		/// </summary>
-		public bool OptInRBF
+		public bool RBF
 		{
 			get;
 			set;
-		}
-
+		}
+
 		/// <summary>
 		/// If true and the transaction has two outputs sending to the same scriptPubKey, those will be merged into a single output. (Default: true)
 		/// </summary>