fix: [ASAN] null pointer in trow.c

source/common/src/trow.c

@@ -412,7 +412,9 @@ int32_t tdSTSRowNew(SArray *pArray, STSchema *pTSchema, STSRow **ppRow) {
         valType = TD_VTYPE_NULL;
       } else if (IS_VAR_DATA_TYPE(pTColumn->type)) {
         varDataSetLen(varBuf, pColVal->value.nData);
-        memcpy(varDataVal(varBuf), pColVal->value.pData, pColVal->value.nData);
+        if (pColVal->value.nData != 0) {
+          memcpy(varDataVal(varBuf), pColVal->value.pData, pColVal->value.nData);
+        }
         val = varBuf;
       } else {
         val = (const void *)&pColVal->value.val;
@@ -1094,4 +1096,4 @@ void tTSRowGetVal(STSRow *pRow, STSchema *pTSchema, int16_t iCol, SColVal *pColV
       memcpy(&pColVal->value.val, cv.val, tDataTypes[pTColumn->type].bytes);
     }
   }
-}
+}
\ No newline at end of file