Add check to ensure close_profit_abs is filled on closed trades

Technically, this should not be possible, but #4554 shows it is.

closes #4554

freqtrade/wallets.py

@@ -71,7 +71,8 @@ class Wallets:
         # TODO: potentially remove the ._log workaround to determine backtest mode.
         if self._log:
             closed_trades = Trade.get_trades_proxy(is_open=False)
-            tot_profit = sum([trade.close_profit_abs for trade in closed_trades])
+            tot_profit = sum(
+                [trade.close_profit_abs for trade in closed_trades if trade.close_profit_abs])
         else:
             tot_profit = LocalTrade.total_profit
         tot_in_trades = sum([trade.stake_amount for trade in open_trades])

tests/test_persistence.py

@@ -1066,8 +1066,14 @@ def test_get_trades_proxy(fee, use_db):
 
     assert isinstance(trades[0], Trade)
 
-    assert len(Trade.get_trades_proxy(is_open=True)) == 4
-    assert len(Trade.get_trades_proxy(is_open=False)) == 2
+    trades = Trade.get_trades_proxy(is_open=True)
+    assert len(trades) == 4
+    assert trades[0].is_open
+    trades = Trade.get_trades_proxy(is_open=False)
+
+    assert len(trades) == 2
+    assert not trades[0].is_open
+
     opendate = datetime.now(tz=timezone.utc) - timedelta(minutes=15)
 
     assert len(Trade.get_trades_proxy(open_date=opendate)) == 3