restrict lightning to p2wpkh wallets

electrum/gui/kivy/uix/ui_screens/status.kv

@@ -31,7 +31,7 @@ Popup:
                         value: app.wallet.wallet_type
                     BoxLabel:
                         text: _("Lightning:")
-                        value: _('Enabled') if app.wallet.has_lightning() else _('Disabled')
+                        value: (_('Enabled') if app.wallet.has_lightning() else _('Disabled')) if app.wallet.can_have_lightning() else _('Not available')
                     BoxLabel:
                         text: _("Balance") + ':'
                         value: app.format_amount_and_units(root.confirmed + root.unconfirmed + root.unmatured)
@@ -90,6 +90,7 @@ Popup:
             Button:
                 size_hint: 0.5, None
                 height: '48dp'
+                disabled: not app.wallet.can_have_lightning()
                 text: _('Disable LN') if app.wallet.has_lightning() else _('Enable LN')
                 on_release:
                     root.dismiss()

electrum/gui/qt/main_window.py

@@ -2190,6 +2190,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
             ks_type = str(keystore_types[0]) if keystore_types else _('No keystore')
             grid.addWidget(QLabel(ks_type), 4, 1)
         # lightning
+        if self.wallet.can_have_lightning():
             if self.wallet.has_lightning():
                 lightning_b = QPushButton(_('Disable'))
                 lightning_b.clicked.connect(dialog.close)

electrum/lnpeer.py

@@ -474,8 +474,10 @@ class Peer(Logger):
             initial_msat = push_msat
 
         if self.is_static_remotekey():
-            addr = self.lnworker.wallet.get_unused_address()
+            wallet = self.lnworker.wallet
-            static_key = self.lnworker.wallet.get_public_key(addr) # just a pubkey
+            assert wallet.txin_type == 'p2wpkh'
+            addr = wallet.get_unused_address()
+            static_key = wallet.get_public_key(addr) # just a pubkey
             payment_basepoint = OnlyPubkeyKeypair(bfh(static_key))
         else:
             payment_basepoint = keypair_generator(LnKeyFamily.PAYMENT_BASE)

electrum/wallet.py

@@ -280,7 +280,12 @@ class Abstract_Wallet(AddressSynchronizer, ABC):
     def has_lightning(self):
         return bool(self.lnworker)
 
+    def can_have_lightning(self):
+        # we want static_remotekey to be a wallet address
+        return self.txin_type == 'p2wpkh'
+
     def init_lightning(self):
+        assert self.can_have_lightning()
         if self.db.get('lightning_privkey2'):
             return
         # TODO derive this deterministically from wallet.keystore at keystore generation time