From 2274bf4467b76d08e4d413f7579bb604e32b4590 Mon Sep 17 00:00:00 2001
From: dmichalowicz <dmichalowicz@quantopian.com>
Date: Tue, 7 Mar 2017 11:38:32 -0500
Subject: [PATCH] BUG: Set data portal last trading session if passed

---
 zipline/data/data_portal.py | 46 ++++++++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/zipline/data/data_portal.py b/zipline/data/data_portal.py
index e833b69b..3b77cdaa 100644
--- a/zipline/data/data_portal.py
+++ b/zipline/data/data_portal.py
@@ -166,15 +166,35 @@ class DataPortal(object):
         self._augmented_sources_map = {}
         self._extra_source_df = None
 
-        self._first_trading_session = first_trading_day
+        self._first_available_session = first_trading_day
 
-        _last_sessions = [r.last_available_dt
-                          for r in [equity_daily_reader, future_daily_reader]
-                          if r is not None]
-        if _last_sessions:
-            self._last_trading_session = min(_last_sessions)
+        if last_available_session:
+            self._last_available_session = last_available_session
         else:
-            self._last_trading_session = None
+            # Infer the last session from the provided readers.
+            last_sessions = [
+                reader.last_available_dt
+                for reader in [equity_daily_reader, future_daily_reader]
+                if reader is not None
+            ]
+            if last_sessions:
+                self._last_available_session = min(last_sessions)
+            else:
+                self._last_available_session = None
+
+        if last_available_minute:
+            self._last_available_minute = last_available_minute
+        else:
+            # Infer the last minute from the provided readers.
+            last_minutes = [
+                reader.last_available_dt
+                for reader in [equity_minute_reader, future_minute_reader]
+                if reader is not None
+            ]
+            if last_minutes:
+                self._last_available_minute = min(last_minutes)
+            else:
+                self._last_available_minute = None
 
         aligned_equity_minute_reader = self._ensure_reader_aligned(
             equity_minute_reader)
@@ -223,14 +243,14 @@ class DataPortal(object):
             self.trading_calendar,
             self.asset_finder,
             aligned_minute_readers,
-            last_available_minute,
+            self._last_available_minute,
         )
 
         _dispatch_session_reader = AssetDispatchSessionBarReader(
             self.trading_calendar,
             self.asset_finder,
             aligned_session_readers,
-            last_available_session,
+            self._last_available_session,
         )
 
         self._pricing_readers = {
@@ -286,15 +306,15 @@ class DataPortal(object):
             return ReindexMinuteBarReader(
                 self.trading_calendar,
                 reader,
-                self._first_trading_session,
-                self._last_trading_session
+                self._first_available_session,
+                self._last_available_session
             )
         elif reader.data_frequency == 'session':
             return ReindexSessionBarReader(
                 self.trading_calendar,
                 reader,
-                self._first_trading_session,
-                self._last_trading_session
+                self._first_available_session,
+                self._last_available_session
             )
 
     def _reindex_extra_source(self, df, source_date_index):