qt ChannelsList: fix opening channel with "max" amount

electrum/gui/qt/channels_list.py

@@ -15,6 +15,7 @@ from electrum.lnchannel import AbstractChannel, PeerState, ChannelBackup, Channe
 from electrum.wallet import Abstract_Wallet
 from electrum.lnutil import LOCAL, REMOTE, format_short_channel_id, LN_MAX_FUNDING_SAT
 from electrum.lnworker import LNWallet
+from electrum import ecc
 
 from .util import (MyTreeView, WindowModalDialog, Buttons, OkButton, CancelButton,
                    EnterButton, WaitingDialog, MONOSPACE_FONT, ColorScheme)
@@ -414,7 +415,8 @@ class ChannelsList(MyTreeView):
             amount_e.setFrozen(max_button.isChecked())
             if not max_button.isChecked():
                 return
-            make_tx = self.parent.mktx_for_open_channel('!')
+            dummy_nodeid = ecc.GENERATOR.get_public_key_bytes(compressed=True)
+            make_tx = self.parent.mktx_for_open_channel(funding_sat='!', node_id=dummy_nodeid)
             try:
                 tx = make_tx(None)
             except (NotEnoughFunds, NoDynamicFeeEstimates) as e:

electrum/gui/qt/main_window.py

@@ -1796,7 +1796,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
         WaitingDialog(self, _('Broadcasting transaction...'),
                       broadcast_thread, broadcast_done, self.on_error)
 
-    def mktx_for_open_channel(self, funding_sat, node_id):
+    def mktx_for_open_channel(self, *, funding_sat, node_id):
         coins = self.get_coins(nonlocal_only=True)
         make_tx = lambda fee_est: self.wallet.lnworker.mktx_for_open_channel(
             coins=coins,
@@ -1813,7 +1813,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
             return
         # use ConfirmTxDialog
         # we need to know the fee before we broadcast, because the txid is required
-        make_tx = self.mktx_for_open_channel(funding_sat, node_id)
+        make_tx = self.mktx_for_open_channel(funding_sat=funding_sat, node_id=node_id)
         d = ConfirmTxDialog(window=self, make_tx=make_tx, output_value=funding_sat, is_sweep=False)
         # disable preview button because the user must not broadcast tx before establishment_flow
         d.preview_button.setEnabled(False)