Merge pull request #6134 from SomberNight/202004_ln_fundingtx_forbid_bump_cjoin

wallet: disallow fee-bumping/coinjoining ln funding tx

electrum/gui/qt/transaction_dialog.py

@@ -170,9 +170,9 @@ class BaseTxDialog(QDialog, MessageBoxMixin):
         ptx_merge_sigs_action = QAction(_("Merge signatures from"), self)
         ptx_merge_sigs_action.triggered.connect(self.merge_sigs)
         partial_tx_actions_menu.addAction(ptx_merge_sigs_action)
-        ptx_join_txs_action = QAction(_("Join inputs/outputs"), self)
-        ptx_join_txs_action.triggered.connect(self.join_tx_with_another)
-        partial_tx_actions_menu.addAction(ptx_join_txs_action)
+        self._ptx_join_txs_action = QAction(_("Join inputs/outputs"), self)
+        self._ptx_join_txs_action.triggered.connect(self.join_tx_with_another)
+        partial_tx_actions_menu.addAction(self._ptx_join_txs_action)
         self.partial_tx_actions_button = QToolButton()
         self.partial_tx_actions_button.setText(_("Combine"))
         self.partial_tx_actions_button.setMenu(partial_tx_actions_menu)
@@ -499,6 +499,8 @@ class BaseTxDialog(QDialog, MessageBoxMixin):
                 widget.menuAction().setVisible(show_psbt_only_widgets)
             else:
                 widget.setVisible(show_psbt_only_widgets)
+        if tx_details.is_lightning_funding_tx:
+            self._ptx_join_txs_action.setEnabled(False)  # would change txid
 
         self.save_button.setEnabled(tx_details.can_save_as_local)
         if tx_details.can_save_as_local:

electrum/wallet.py

@@ -208,6 +208,7 @@ class TxWalletDetails(NamedTuple):
     tx_mined_status: TxMinedInfo
     mempool_depth_bytes: Optional[int]
     can_remove: bool  # whether user should be allowed to delete tx
+    is_lightning_funding_tx: bool
 
 
 class Abstract_Wallet(AddressSynchronizer, ABC):
@@ -521,7 +522,11 @@ class Abstract_Wallet(AddressSynchronizer, ABC):
         exp_n = None
         can_broadcast = False
         can_bump = False
-        tx_hash = tx.txid()
+        tx_hash = tx.txid()  # note: txid can be None! e.g. when called from GUI tx dialog
+        is_lightning_funding_tx = False
+        if self.has_lightning() and tx_hash is not None:
+            is_lightning_funding_tx = any([chan.funding_outpoint.txid == tx_hash
+                                           for chan in self.lnworker.channels.values()])
         tx_we_already_have_in_db = self.db.get_transaction(tx_hash)
         can_save_as_local = (is_relevant and tx.txid() is not None
                              and (tx_we_already_have_in_db is None or not tx_we_already_have_in_db.is_complete()))
@@ -571,6 +576,9 @@ class Abstract_Wallet(AddressSynchronizer, ABC):
         else:
             amount = None
 
+        if is_lightning_funding_tx:
+            can_bump = False  # would change txid
+
         return TxWalletDetails(
             txid=tx_hash,
             status=status,
@@ -583,6 +591,7 @@ class Abstract_Wallet(AddressSynchronizer, ABC):
             tx_mined_status=tx_mined_status,
             mempool_depth_bytes=exp_n,
             can_remove=can_remove,
+            is_lightning_funding_tx=is_lightning_funding_tx,
         )
 
     def get_spendable_coins(self, domain, *, nonlocal_only=False) -> Sequence[PartialTxInput]: