fix bug

src/inc/tsdb.h

@@ -268,6 +268,8 @@ TsdbQueryHandleT tsdbQueryLastRow(STsdbRepo *tsdb, STsdbQueryCond *pCond, STable
 
 TsdbQueryHandleT tsdbQueryCacheLast(STsdbRepo *tsdb, STsdbQueryCond *pCond, STableGroupInfo *groupList, uint64_t qId, SMemRef* pMemRef);
 
+bool isTsdbCacheLastRow(TsdbQueryHandleT* pQueryHandle);
+
 
 /**
  * get the queried table object list

src/query/src/qExecutor.c

@@ -4243,7 +4243,7 @@ static SSDataBlock* doTableScan(void* param, bool *newgroup) {
     }
 
     if (++pTableScanInfo->current >= pTableScanInfo->times) {
-      if (pTableScanInfo->reverseTimes <= 0) {
+      if (pTableScanInfo->reverseTimes <= 0 || isTsdbCacheLastRow(pTableScanInfo->pQueryHandle)) {
         return NULL;
       } else {
         break;

src/tsdb/src/tsdbRead.c

@@ -547,7 +547,9 @@ TsdbQueryHandleT tsdbQueryCacheLast(STsdbRepo *tsdb, STsdbQueryCond *pCond, STab
     return NULL;
   }
 
+  if (pQueryHandle->cachelastrow) {
     pQueryHandle->type = TSDB_QUERY_TYPE_LAST;
+  }
   
   return pQueryHandle;
 }
@@ -2873,6 +2875,10 @@ int32_t tsdbGetCachedLastRow(STable* pTable, SDataRow* pRes, TSKEY* lastKey) {
   return TSDB_CODE_SUCCESS;
 }
 
+bool isTsdbCacheLastRow(TsdbQueryHandleT* pQueryHandle) {
+  return ((STsdbQueryHandle *)pQueryHandle)->cachelastrow > 0;
+}
+
 int32_t checkForCachedLastRow(STsdbQueryHandle* pQueryHandle, STableGroupInfo *groupList) {
   assert(pQueryHandle != NULL && groupList != NULL);
 
@@ -2922,7 +2928,6 @@ int32_t checkForCachedLast(STsdbQueryHandle* pQueryHandle, STableGroupInfo *grou
     pQueryHandle->cachelastrow = 2;
   }
 
-
   // update the tsdb query time range
   if (pQueryHandle->cachelastrow) {
     pQueryHandle->window      = TSWINDOW_INITIALIZER;