Merge pull request #2203 from hackaugusto/fix_2071

Send secret reveal once

raiden/transfer/mediated_transfer/mediator.py

@@ -624,8 +624,9 @@ def events_for_revealsecret(transfers_pair, secret, pseudo_random_generator):
     for pair in reversed(transfers_pair):
         payee_secret = pair.payee_state in STATE_SECRET_KNOWN
         payer_secret = pair.payer_state in STATE_SECRET_KNOWN
+        should_send_secret = pair.payer_state == 'payer_pending'
 
-        if payee_secret and not payer_secret:
+        if payee_secret and not payer_secret and should_send_secret:
             message_identifier = message_identifier_from_prng(pseudo_random_generator)
             pair.payer_state = 'payer_secret_revealed'
             payer_transfer = pair.payer_transfer

raiden/transfer/mediated_transfer/target.py

@@ -145,8 +145,9 @@ def handle_secretreveal(
 ):
     """ Validates and handles a ReceiveSecretReveal state change. """
     valid_secret = state_change.secrethash == target_state.transfer.lock.secrethash
+    waiting_for_secret = target_state.state == 'secret_request'
 
-    if valid_secret:
+    if valid_secret and waiting_for_secret:
         if isinstance(state_change, ReceiveSecretReveal):
             channel.register_secret(
                 channel_state,
@@ -167,6 +168,9 @@ def handle_secretreveal(
         target_state.state = 'reveal_secret'
         target_state.secret = state_change.secret
         recipient = route.node_address
+
+        # Send the secret reveal message only once, delivery is guaranteed by
+        # the transport and not by the state machine
         reveal = SendRevealSecret(
             recipient=recipient,
             channel_identifier=CHANNEL_IDENTIFIER_GLOBAL_QUEUE,