qt/kivy ChannelsList: if node alias is unknown, display node id

instead of "unknown"

electrum/gui/kivy/uix/dialogs/lightning_channels.py

@@ -594,7 +594,7 @@ class LightningChannelsDialog(Factory.Popup):
             item.active = not i.is_closed()
             item.is_backup = i.is_backup()
             item._chan = i
-            item.node_alias = lnworker.get_node_alias(i.node_id)
+            item.node_alias = lnworker.get_node_alias(i.node_id) or i.node_id.hex()
             self.update_item(item)
             channel_cards.add_widget(item)
         self.update_can_send()

electrum/gui/qt/channels_list.py

@@ -85,7 +85,7 @@ class ChannelsList(MyTreeView):
             labels[subject] = label
         status = chan.get_state_for_GUI()
         closed = chan.is_closed()
-        node_alias = self.lnworker.get_node_alias(chan.node_id)
+        node_alias = self.lnworker.get_node_alias(chan.node_id) or chan.node_id.hex()
         if isinstance(chan, Channel):
             capacity_str = self.parent.format_amount(chan.constraints.capacity)
         else:

electrum/lnworker.py

@@ -270,17 +270,18 @@ class LNWorker(Logger, NetworkRetryManager[LNPeerAddr]):
     def channels_for_peer(self, node_id: bytes) -> Dict[bytes, Channel]:
         return {}
 
-    def get_node_alias(self, node_id: bytes) -> str:
+    def get_node_alias(self, node_id: bytes) -> Optional[str]:
+        """Returns the alias of the node, or None if unknown."""
+        node_alias = None
         if self.channel_db:
             node_info = self.channel_db.get_node_info_for_node_id(node_id)
-            node_alias = (node_info.alias if node_info else '') or node_id.hex()
+            if node_info:
+                node_alias = node_info.alias
         else:
             for k, v in hardcoded_trampoline_nodes().items():
                 if v.pubkey == node_id:
                     node_alias = k
                     break
-            else:
-                node_alias = 'unknown'
         return node_alias
 
     async def maybe_listen(self):