add_channel must not overwrite existing channel

raiden/network/channelgraph.py

@@ -195,8 +195,7 @@ def __init__(
             channelmanager_address,
             token_address,
             edge_list,
-            channels_details,
-            block_number):
+            channels_details):
 
         if not isaddress(token_address):
             raise ValueError('token_address must be a valid address')
@@ -236,21 +235,32 @@ def __ne__(self, other):
         return not self.__eq__(other)
 
     def add_channel(self, details):
+        """ Instantiate a channel this node participates and add to the graph.
+
+        If the channel is already registered do nothing.
+        """
         channel_address = details.channel_address
-        partner_state = details.partner_state
-
-        channel = Channel(
-            details.our_state,
-            partner_state,
-            details.external_state,
-            self.token_address,
-            details.reveal_timeout,
-            details.settle_timeout,
-        )
-        self.add_path(details.our_state.address, partner_state.address)
-
-        self.partneraddress_to_channel[partner_state.address] = channel
-        self.address_to_channel[channel_address] = channel
+
+        if details.our_state.address != self.our_address:
+            raise ValueError(
+                "Address mismatch, our_address doesn't match the channel details"
+            )
+
+        if channel_address not in self.address_to_channel:
+            partner_state = details.partner_state
+
+            channel = Channel(
+                details.our_state,
+                partner_state,
+                details.external_state,
+                self.token_address,
+                details.reveal_timeout,
+                details.settle_timeout,
+            )
+            self.add_path(details.our_state.address, partner_state.address)
+
+            self.partneraddress_to_channel[partner_state.address] = channel
+            self.address_to_channel[channel_address] = channel
 
     def get_channel_by_contract_address(self, netting_channel_address):
         """ Return the channel with `netting_channel_address`.

raiden/raiden_service.py

@@ -640,8 +640,6 @@ def register_registry(self, registry_address):
         # some events might be applied twice.
         self.pyethapp_blockchain_events.add_proxies_listeners(proxies)
 
-        block_number = self.get_block_number()
-
         for manager in proxies.channel_managers:
             token_address = manager.token_address()
             manager_address = manager.address
@@ -659,7 +657,6 @@ def register_registry(self, registry_address):
                 token_address,
                 edge_list,
                 channels_detail,
-                block_number,
             )
 
             self.manager_to_token[manager_address] = token_address
@@ -700,14 +697,12 @@ def register_channel_manager(self, manager_address):
             for channel in netting_channels
         ]
 
-        block_number = self.get_block_number()
         graph = ChannelGraph(
             self.address,
             manager_address,
             token_address,
             edge_list,
             channels_detail,
-            block_number,
         )
 
         self.manager_to_token[manager_address] = token_address

raiden/tests/unit/test_channelgraph.py

@@ -0,0 +1,63 @@
+# -*- coding: utf-8 -*-
+from raiden.network.channelgraph import ChannelGraph, ChannelDetails
+from raiden.tests.utils.factories import make_address
+
+
+class ParticipantStateMock(object):
+    def __init__(self, address):
+        self.address = address
+
+
+class NettingChannelMock(object):
+    def __init__(self, address):
+        self.address = address
+
+
+class ExternalStateMock(object):
+    def __init__(self, netting_channel):
+        self.netting_channel = netting_channel
+        self.settled_block = 0
+        self.closed_block = 0
+        self.opened_block = 0
+
+
+def test_addchannel_must_not_overwrite():  # pylint: disable=too-many-locals
+    """ Calling add_channel for an existing channel must not overwrite it. """
+    our_address = make_address()
+    partner_address = make_address()
+    channel_manager_address = make_address()
+    token_address = make_address()
+    channel_address = make_address()
+
+    our_state = ParticipantStateMock(our_address)
+    partner_state = ParticipantStateMock(partner_address)
+    netting_channel = NettingChannelMock(channel_address)
+    external_state = ExternalStateMock(netting_channel)
+    reveal_timeout = 5
+    settle_timeout = 10
+
+    channel_detail = ChannelDetails(
+        channel_address,
+        our_state,
+        partner_state,
+        external_state,
+        reveal_timeout,
+        settle_timeout,
+    )
+
+    edge_list = []
+    channel_detail_list = [channel_detail]
+
+    graph = ChannelGraph(
+        our_address,
+        channel_manager_address,
+        token_address,
+        edge_list,
+        channel_detail_list,
+    )
+
+    first_instance = graph.address_to_channel[channel_address]
+
+    graph.add_channel(channel_detail)
+
+    assert first_instance is graph.address_to_channel[channel_address]