From de098c79eade9fc6e52d9d5b1b6e77cf2a086e44 Mon Sep 17 00:00:00 2001
From: Dylan Wilson <dylanjw@protonmail.com>
Date: Mon, 30 Jul 2018 10:24:15 -0700
Subject: [PATCH] Disallow merging topic lists

---
 ...est_contract_createFilter_topic_merging.py | 27 ++++++-------------
 web3/utils/filters.py                         |  9 ++++---
 2 files changed, 13 insertions(+), 23 deletions(-)

diff --git a/tests/core/filtering/test_contract_createFilter_topic_merging.py b/tests/core/filtering/test_contract_createFilter_topic_merging.py
index 76b177ada6..61ed78c173 100644
--- a/tests/core/filtering/test_contract_createFilter_topic_merging.py
+++ b/tests/core/filtering/test_contract_createFilter_topic_merging.py
@@ -1,3 +1,6 @@
+import pytest
+
+
 def test_merged_topic_list_event(
         web3,
         emitter,
@@ -9,22 +12,8 @@ def test_merged_topic_list_event(
         '0x0000000000000000000000000000000000000000000000000000000000000457',  # 1111
         '0x0000000000000000000000000000000000000000000000000000000000000457',  # 1111
     ]
-    log_filter = emitter.events.LogTripleWithIndex().createFilter(
-        fromBlock="latest",
-        topics=manual_topics,
-        argument_filters={'arg0': 2222, 'arg1': 2222, 'arg2': 2222})
-    event_id = getattr(emitter_event_ids, 'LogTripleWithIndex')
-    txn_hashes = [
-        emitter.functions.logTriple(event_id, 1111, 1111, 1111).transact(),
-        emitter.functions.logTriple(event_id, 1111, 1111, 2222).transact(),
-        emitter.functions.logTriple(event_id, 1111, 2222, 1111).transact(),
-        emitter.functions.logTriple(event_id, 2222, 1111, 1111).transact(),
-        emitter.functions.logTriple(event_id, 2222, 1111, 2222).transact(),
-        emitter.functions.logTriple(event_id, 1111, 2222, 2222).transact(),
-        emitter.functions.logTriple(event_id, 2222, 2222, 1111).transact(),
-        emitter.functions.logTriple(event_id, 2222, 2222, 2222).transact()
-    ]
-    while True:
-        if all(wait_for_transaction(web3, txn_hash) for txn_hash in txn_hashes):
-            break
-    assert len(log_filter.get_all_entries()) == 2
+    with pytest.raises(TypeError):
+        emitter.events.LogTripleWithIndex().createFilter(
+            fromBlock="latest",
+            topics=manual_topics,
+            argument_filters={'arg0': 2222, 'arg1': 2222, 'arg2': 2222})
diff --git a/web3/utils/filters.py b/web3/utils/filters.py
index caccf65072..3dd26b9981 100644
--- a/web3/utils/filters.py
+++ b/web3/utils/filters.py
@@ -26,11 +26,12 @@ def construct_event_filter_params(event_abi,
                                   toBlock=None,
                                   address=None):
     filter_params = {}
+    topic_set = construct_event_topic_set(event_abi, argument_filters)
 
-    if topics is None:
-        topic_set = construct_event_topic_set(event_abi, argument_filters)
-    else:
-        topic_set = [topics] + construct_event_topic_set(event_abi, argument_filters)
+    if topics is not None and len(topic_set) != 0:
+        raise TypeError(
+            "Merging the topics argument with topics generated "
+            "from argument_filters is not supported.")
 
     if len(topic_set) == 1 and is_list_like(topic_set[0]):
         filter_params['topics'] = topic_set[0]