Do not force mutate eth accounts to be checksummed

Fix rotki#519.

This should no longer happen. The very first upgrade of the DB turned
all address entries into checksummed entries. Since then we make sure
to always add addresses as checksummed in the DB and the API also
makes sure that all address input is checksummed.

So this commit closes the chapter by warning the user if a
non-checksummed eth account is found in his DB. But the only way this
happens is if the user manually edits it.

rotkehlchen/blockchain.py

@@ -57,12 +57,7 @@ def __init__(
         self.ethchain = ethchain
         self.msg_aggregator = msg_aggregator
         self.owned_eth_tokens = owned_eth_tokens
-
         self.accounts = blockchain_accounts
-        # go through ETH accounts and make sure they are EIP55 encoded
-        # TODO: really really bad thing here. Should not have to force mutate
-        # a named tuple. Move this into the named tuple constructor
-        self.accounts._replace(eth=[to_checksum_address(x) for x in self.accounts.eth])
 
         # Per account balances
         self.balances: Balances = defaultdict(dict)

rotkehlchen/db/dbhandler.py

@@ -8,7 +8,7 @@
 from json.decoder import JSONDecodeError
 from typing import Any, Dict, List, Optional, Set, Tuple, cast
 
-from eth_utils import to_checksum_address
+from eth_utils import is_checksum_address, to_checksum_address
 from pysqlcipher3 import dbapi2 as sqlcipher
 from typing_extensions import Literal
 
@@ -644,6 +644,14 @@ def get_blockchain_accounts(self) -> BlockchainAccounts:
 
         for entry in query:
             if entry[0] == S_ETH:
+                if not is_checksum_address(entry[1]):
+                    self.msg_aggregator.add_warning(
+                        f'Non-checksummed eth address {entry[1]} detected in the DB. This '
+                        f'should not happen unless the DB was manually modified. '
+                        f' Skipping entry. This needs to be fixed manually. If you '
+                        f' can not do that alone ask for help in the issue tracker',
+                    )
+                    continue
                 eth_list.append(entry[1])
             elif entry[0] == S_BTC:
                 btc_list.append(entry[1])

rotkehlchen/tests/db/test_db.py

@@ -900,3 +900,39 @@ def test_add_ethereum_transactions(data_dir, username):
     assert len(warnings) == 0
     returned_transactions = data.db.get_ethereum_transactions()
     assert returned_transactions == [tx1, tx2, tx3]
+
+
+def test_non_checksummed_eth_account_in_db(database):
+    """
+    Regression test for  https://github.com/rotki/rotki/issues/519
+
+    This is a test for an occasion that should not happen in a normal run.
+    Only if the user manually edits the DB and modifies a blockchain account
+    to be non-checksummed then this scenario will happen.
+
+    This test verifies that the user is warned and the address is skipped.
+    """
+    # Manually enter three blockchain ETH accounts one of which is only valid
+    cursor = database.conn.cursor()
+    valid_address = '0x9531C059098e3d194fF87FebB587aB07B30B1306'
+    non_checksummed_address = '0xe7302e6d805656cf37bd6839a977fe070184bf45'
+    invalid_address = 'dsads'
+    cursor.executemany(
+        'INSERT INTO blockchain_accounts(blockchain, account) VALUES (?, ?)',
+        (
+            ('ETH', non_checksummed_address),
+            ('ETH', valid_address),
+            ('ETH', invalid_address)),
+    )
+    database.conn.commit()
+
+    blockchain_accounts = database.get_blockchain_accounts()
+    eth_accounts = blockchain_accounts.eth
+    assert len(eth_accounts) == 1
+    assert eth_accounts[0] == valid_address
+    errors = database.msg_aggregator.consume_errors()
+    warnings = database.msg_aggregator.consume_warnings()
+    assert len(errors) == 0
+    assert len(warnings) == 2
+    assert f'Non-checksummed eth address {non_checksummed_address}' in warnings[0]
+    assert f'Non-checksummed eth address {invalid_address}' in warnings[1]