TD-728: add test case to reproduce select last crash

tests/pytest/fulltest.sh

@@ -142,6 +142,7 @@ python3 ./test.py -f query/filterFloatAndDouble.py
 python3 ./test.py -f query/filterOtherTypes.py
 python3 ./test.py -f query/querySort.py
 python3 ./test.py -f query/queryJoin.py
+python3 ./test.py -f query/select_last_crash.py
 
 #stream
 python3 ./test.py -f stream/stream1.py

tests/pytest/query/select_last_crash.py

+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import taos
+from util.log import *
+from util.cases import *
+from util.sql import *
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        
+        self.rowNum = 5000
+        self.ts = 1537146000000
+
+    def run(self):
+        tdSql.prepare()
+
+        tdSql.execute(
+            "create table if not exists st (ts timestamp, value nchar(50), speed int) tags(dev nchar(50))")
+        tdSql.execute(
+            "create table t1 using st tags('dev_001')")
+
+        for i in range(self.rowNum):
+            tdSql.execute("insert into t1 values(%d, 'taosdata%d', %d)" % (self.ts + i, i + 1, i + 1))
+
+        tdSql.query("select last(*) from st")
+        tdSql.checkRows(1)
+
+        print(
+            "======= Verify filter for %s type finished =========" %
+            curType)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())