Merge pull request #5047 from taosdata/hotfix/TD-2803

[TD-2803]taosd crashes for join query with stddev function

src/query/src/qExecutor.c

@@ -3828,6 +3828,11 @@ void scanOneTableDataBlocks(SQueryRuntimeEnv *pRuntimeEnv, TSKEY start) {
     setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
     pRuntimeEnv->scanFlag = REPEAT_SCAN;
 
+    if (pRuntimeEnv->pTsBuf) {
+      bool ret = tsBufNextPos(pRuntimeEnv->pTsBuf);
+      assert(ret);
+    }
+
     qDebug("QInfo:%p start to repeat scan data blocks due to query func required, qrange:%"PRId64"-%"PRId64, pQInfo,
         cond.twindow.skey, cond.twindow.ekey);
   }