fix: error in empty string in operator

include/util/types.h

@@ -83,6 +83,7 @@ typedef uint16_t VarDataLenT;  // maxVarDataLen: 32767
 
 #define varDataLen(v) ((VarDataLenT *)(v))[0]
 #define varDataVal(v) ((char *)(v) + VARSTR_HEADER_SIZE)
+#define varDataTLen(v) (sizeof(VarDataLenT) + varDataLen(v))
 
 #define NCHAR_WIDTH_TO_BYTES(n)  ((n) * TSDB_NCHAR_SIZE + VARSTR_HEADER_SIZE)
 

source/libs/scalar/src/scalar.c

@@ -109,9 +109,8 @@ int32_t scalarGenerateSetFromList(void **data, void *pNode, uint32_t type) {
       }
 
       if (IS_VAR_DATA_TYPE(type)) {
-        char* data = colDataGetVarData(out.columnData, 0);
-        len = varDataLen(data);
-        buf = varDataVal(data);
+        buf = colDataGetVarData(out.columnData, 0);
+        len = varDataTLen(data);
       } else {
         len = tDataTypes[type].bytes;
         buf = out.columnData->pData;
@@ -119,8 +118,7 @@ int32_t scalarGenerateSetFromList(void **data, void *pNode, uint32_t type) {
     } else {
       buf = nodesGetValueFromNode(valueNode);
       if (IS_VAR_DATA_TYPE(type)) {
-        len = varDataLen(buf);
-        buf = varDataVal(buf);
+        len = varDataTLen(buf);
       } else {
         len = valueNode->node.resType.bytes;
       }

source/util/src/tcompare.c

@@ -56,11 +56,11 @@ int32_t setChkNotInBytes8(const void *pLeft, const void *pRight) {
 }
 
 int32_t compareChkInString(const void *pLeft, const void *pRight) {
-  return NULL != taosHashGet((SHashObj *)pRight, varDataVal(pLeft), varDataLen(pLeft)) ? 1 : 0;
+  return NULL != taosHashGet((SHashObj *)pRight, pLeft, varDataTLen(pLeft)) ? 1 : 0;
 }
 
 int32_t compareChkNotInString(const void *pLeft, const void *pRight) {
-  return NULL == taosHashGet((SHashObj *)pRight, varDataVal(pLeft), varDataLen(pLeft)) ? 1 : 0;
+  return NULL == taosHashGet((SHashObj *)pRight, pLeft, varDataTLen(pLeft)) ? 1 : 0;
 }
 
 int32_t compareInt8Val(const void *pLeft, const void *pRight) {