From 6e2290c4f0d142de4e924f7ee78b209d90ec3643 Mon Sep 17 00:00:00 2001
From: Matthias <xmatthias@outlook.com>
Date: Mon, 2 Mar 2020 20:05:54 +0100
Subject: [PATCH] Allow last to be empty -

closes #3005
---
 freqtrade/freqtradebot.py  | 8 +++-----
 tests/test_freqtradebot.py | 8 ++++++++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/freqtrade/freqtradebot.py b/freqtrade/freqtradebot.py
index 53493ad4c..04e3dd72f 100644
--- a/freqtrade/freqtradebot.py
+++ b/freqtrade/freqtradebot.py
@@ -257,12 +257,10 @@ class FreqtradeBot:
         else:
             logger.info(f"Using Last {bid_strategy['price_side'].capitalize()} / Last Price")
             ticker = self.exchange.fetch_ticker(pair)
-            rate = ticker[bid_strategy['price_side']]
-            if rate < ticker['last']:
-                ticker_rate = rate
-            else:
+            ticker_rate = ticker[bid_strategy['price_side']]
+            if ticker['last'] and ticker_rate > ticker['last']:
                 balance = self.config['bid_strategy']['ask_last_balance']
-                ticker_rate = rate + balance * (ticker['last'] - rate)
+                ticker_rate = ticker_rate + balance * (ticker['last'] - ticker_rate)
             used_rate = ticker_rate
 
         self._buy_rate_cache[pair] = used_rate
diff --git a/tests/test_freqtradebot.py b/tests/test_freqtradebot.py
index 49000382f..a5506017c 100644
--- a/tests/test_freqtradebot.py
+++ b/tests/test_freqtradebot.py
@@ -914,6 +914,10 @@ def test_process_informative_pairs_added(default_conf, ticker, mocker) -> None:
     ('ask', 20, 19, 10, 0.3, 17),  # Between ask and last
     ('ask', 5, 6, 10, 1.0, 5),  # last bigger than ask
     ('ask', 5, 6, 10, 0.5, 5),  # last bigger than ask
+    ('ask', 10, 20, None, 0.5, 10),  # last not available - uses ask
+    ('ask', 4, 5, None, 0.5, 4),  # last not available - uses ask
+    ('ask', 4, 5, None, 1, 4),  # last not available - uses ask
+    ('ask', 4, 5, None, 0, 4),  # last not available - uses ask
     ('bid', 10, 20, 10, 0.0, 20),  # Full bid side
     ('bid', 10, 20, 10, 1.0, 10),  # Full last side
     ('bid', 10, 20, 10, 0.5, 15),  # Between bid and last
@@ -921,6 +925,10 @@ def test_process_informative_pairs_added(default_conf, ticker, mocker) -> None:
     ('bid', 10, 20, 10, 0.3, 17),  # Between bid and last
     ('bid', 4, 5, 10, 1.0, 5),  # last bigger than bid
     ('bid', 4, 5, 10, 0.5, 5),  # last bigger than bid
+    ('bid', 10, 20, None, 0.5, 20),  # last not available - uses bid
+    ('bid', 4, 5, None, 0.5, 5),  # last not available - uses bid
+    ('bid', 4, 5, None, 1, 5),  # last not available - uses bid
+    ('bid', 4, 5, None, 0, 5),  # last not available - uses bid
 ])
 def test_get_buy_rate(mocker, default_conf, caplog, side, ask, bid,
                       last, last_ab, expected) -> None: