Merge JoinMarket-Org/joinmarket-clientserver#1604: Allow fee bump tx not signalling BIP125 if `mempoolfullrbf` is enabled

c990a4da6b Allow fee bump tx not signalling BIP125 if mempoolfullrbf is enabled (Kristaps Kaupe)

Pull request description:

  We should allow this if full-RBF is enabled in Bitcoin node.

ACKs for top commit:
  AdamISZ:
    utACK c990a4da6b

Tree-SHA512: a2bb2374e790891d437ee71647c15ad91eb855ae5bd99afa8e116b91d15bdd4a9f3694469a867f24a37612c38e4215bfb1d45beda8fc921b3dc4363d5d015fd0

scripts/bumpfee.py

@@ -74,8 +74,10 @@ def check_valid_candidate(orig_tx, wallet, output_index=-1):
     if own_inputs_n != tx_inputs_n:
         raise ValueError('Transaction inputs should belong to the wallet.')
 
-    # at least one input should signal opt-in rbf
-    if not any([vin.nSequence <= 0xffffffff - 2 for vin in orig_tx.vin]):
+    # either mempoolfullrbf must be enabled or at least one input must signal
+    # opt-in rbf
+    if not jm_single().bc_interface.mempoolfullrbf() and \
+       not any([vin.nSequence <= 0xffffffff - 2 for vin in orig_tx.vin]):
         raise ValueError('Transaction not replaceable.')
 
     # 1. If output_index is specified, check that the output exist

src/jmclient/blockchaininterface.py

@@ -171,6 +171,11 @@ class BlockchainInterface(ABC):
         """Checks that raw transaction would be accepted by mempool.
         """
 
+    @abstractmethod
+    def mempoolfullrbf(self) -> bool:
+        """Whether mempool full-RBF is enabled.
+        """
+
     @abstractmethod
     def _get_mempool_min_fee(self) -> Optional[int]:
         """Returns minimum mempool fee as a floor to avoid relay problems
@@ -558,13 +563,20 @@ class BitcoinCoreInterface(BlockchainInterface):
                 result.append(result_dict)
         return result
 
+    def _getmempoolinfo(self) -> Optional[dict]:
+        return self._rpc('getmempoolinfo')
+
     def _get_mempool_min_fee(self) -> Optional[int]:
-        rpc_result = self._rpc('getmempoolinfo')
+        rpc_result = self._getmempoolinfo()
         if not rpc_result:
             # in case of connection error:
             return None
         return btc.btc_to_sat(rpc_result['mempoolminfee'])
 
+    def mempoolfullrbf(self) -> bool:
+        rpc_result = self._getmempoolinfo()
+        return 'fullrbf' in rpc_result and rpc_result['fullrbf']
+
     def _estimate_fee_basic(self, conf_target: int) -> Optional[int]:
         # Special bitcoin core case: sometimes the highest priority
         # cannot be estimated in that case the 2nd highest priority

test/jmclient/commontest.py

@@ -90,6 +90,8 @@ class DummyBlockchainInterface(BlockchainInterface):
         pass
     def rescanblockchain(self, start_height: int, end_height: Optional[int] = None) -> None:
         pass
+    def mempoolfullrbf(self) -> bool:
+        pass
 
     def get_current_block_height(self) -> int:
         return 10**6