From 76f38ee03a06807f42e5fd9280c3cd3ec134fc51 Mon Sep 17 00:00:00 2001
From: shenglian zhou <slzhou@taosdata.com>
Date: Sun, 17 Jul 2022 05:19:01 +0800
Subject: [PATCH] feat: change bufSize to leave space for var string header

---
 source/libs/executor/src/scanoperator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index 77427680af..b9bd90fa73 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -1978,7 +1978,7 @@ static SSDataBlock* sysTableScanUserTags(SOperatorInfo* pOperator) {
         }
       }
 
-      int32_t bufSize = IS_VAR_DATA_TYPE(tagType) ? tagLen : 1024;
+      int32_t bufSize = IS_VAR_DATA_TYPE(tagType) ? tagLen + VARSTR_HEADER_SIZE : 1024;
       char*   tagVarChar = NULL;
       if (tagData != NULL) {
         tagVarChar = taosMemoryMalloc(bufSize);