Fixed error when the DHT returns zero peers

src/tribler-core/tribler_core/modules/payout_manager.py

@@ -35,12 +35,14 @@ async def do_payout(self, mid):
             return None
 
         self.logger.debug("Received %d nodes for DHT lookup", len(nodes))
-        if nodes:
-            try:
-                await self.bandwidth_community.do_payout(nodes[0], total_bytes)
-            except Exception as e:
-                self.logger.error("Error while doing bandwidth payout, error %s", e)
-                return None
+        if not nodes:
+            return None
+
+        try:
+            await self.bandwidth_community.do_payout(nodes[0], total_bytes)
+        except Exception as e:
+            self.logger.error("Error while doing bandwidth payout, error %s", e)
+            return None
 
         # Remove the outstanding bytes; otherwise we will payout again
         self.tribler_peers.pop(mid, None)

src/tribler-core/tribler_core/modules/tests/test_payout_manager.py

@@ -54,6 +54,20 @@ def err_connect_peer(_):
     assert not res
 
 
+@pytest.mark.asyncio
+async def test_do_payout_no_dht_peers(payout_manager):
+    """
+    Test whether we are not doing a payout when there are no peers returned by the DHT
+    """
+    def connect_peer(_):
+        return succeed([])
+
+    payout_manager.update_peer(b'a', b'b', 10 * 1024 * 1024)
+    payout_manager.dht.connect_peer = connect_peer
+    res = await payout_manager.do_payout(b'a')
+    assert not res
+
+
 @pytest.mark.asyncio
 async def test_do_payout_error(payout_manager):
     """