[TD-6054]<fix>: Filtered by tag with nchar value not as expected

src/util/src/tcompare.c

@@ -129,7 +129,16 @@ int32_t compareLenPrefixedWStr(const void *pLeft, const void *pRight) {
   if (len1 != len2) {
     return len1 > len2? 1:-1;
   } else {
-    int32_t ret = wcsncmp(varDataVal(pLeft), varDataVal(pRight), len1/TSDB_NCHAR_SIZE);
+    char *pLeftTerm = (char *)tcalloc(len1 + 1, sizeof(char));
+    char *pRightTerm = (char *)tcalloc(len1 + 1, sizeof(char));
+    memcpy(pLeftTerm, varDataVal(pLeft), len1);
+    memcpy(pRightTerm, varDataVal(pRight), len2);
+
+    int32_t ret = wcsncmp((wchar_t*) pLeftTerm, (wchar_t*) pRightTerm, len1/TSDB_NCHAR_SIZE);
+
+    tfree(pLeftTerm);
+    tfree(pRightTerm);
+
     if (ret == 0) {
       return 0;
     } else {
@@ -410,7 +419,16 @@ int32_t doCompare(const char* f1, const char* f2, int32_t type, size_t size) {
         return t1->len > t2->len? 1:-1;
       }
 
-      int32_t ret = wcsncmp((wchar_t*) t1->data, (wchar_t*) t2->data, t2->len/TSDB_NCHAR_SIZE);
+      char *t1_term = (char *)tcalloc(t1->len + 1, sizeof(char));
+      char *t2_term = (char *)tcalloc(t2->len + 1, sizeof(char));
+      memcpy(t1_term, t1->data, t1->len);
+      memcpy(t2_term, t2->data, t2->len);
+
+      int32_t ret = wcsncmp((wchar_t*) t1_term, (wchar_t*) t2_term, t2->len/TSDB_NCHAR_SIZE);
+
+      tfree(t1_term);
+      tfree(t2_term);
+
       if (ret == 0) {
         return ret;
       }

tests/pytest/query/filterWithinMultiNchar.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 tdLog
+from util.cases import tdCases
+from util.sql import tdSql
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+    def run(self):
+        tdSql.prepare()
+
+        print("==============step1")
+        tdSql.execute(
+            "create stable t6 (ts timestamp,val int,flow nchar(36)) tags(dev nchar(36),dev1 nchar(36),dev2 nchar(36))")
+        tdSql.execute("insert into t6004 using t6 (dev,dev1,dev2) tags ('b50c79bc-b102-48e6-bda1-4212263e46d0','b50c79bc-b102-48e6-bda1-4212263e46d0', 'b50c79bc-b102-48e6-bda1-4212263e46d0') values(now,1,'b50c79bc-b102-48e6-bda1-4212263e46d0')")
+
+
+        print("==============step2")
+        tdSql.query("select * from t6 where dev='b50c79bc-b102-48e6-bda1-4212263e46d0'")
+        tdSql.checkRows(1)
+
+        tdSql.query("select * from t6 where dev1='b50c79bc-b102-48e6-bda1-4212263e46d0'")
+        tdSql.checkRows(1)
+
+        tdSql.query("select * from t6 where dev2='b50c79bc-b102-48e6-bda1-4212263e46d0'")
+        tdSql.checkRows(1)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())