From 2735c956248038f9ddce02067dc981f781b481e4 Mon Sep 17 00:00:00 2001
From: hjxilinx <hjxilinx@163.com>
Date: Sat, 1 Feb 2020 23:13:54 +0800
Subject: [PATCH] fix a memory leak for null value projection in tags.

---
 src/system/detail/src/vnodeQueryImpl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/system/detail/src/vnodeQueryImpl.c b/src/system/detail/src/vnodeQueryImpl.c
index 0daa0936e9..760ca94bf9 100644
--- a/src/system/detail/src/vnodeQueryImpl.c
+++ b/src/system/detail/src/vnodeQueryImpl.c
@@ -4525,10 +4525,11 @@ static void doSetTagValueInParam(tTagSchema *pTagSchema, int32_t tagColIdx, SMet
   SSchema *pCol = &pTagSchema->pSchema[tagColIdx];
 
   tVariantDestroy(param);
-  tVariantCreateFromBinary(param, pStr, pCol->bytes, pCol->type);
 
   if (isNull(pStr, pCol->type)) {
     param->nType = TSDB_DATA_TYPE_NULL;
+  } else {
+    tVariantCreateFromBinary(param, pStr, pCol->bytes, pCol->type);
   }
 }