Merge pull request #12150 from taosdata/fix/td-15272

fix: apply function offset/forward step error when session window and order by ts desc

src/query/src/qExecutor.c

@@ -1744,6 +1744,9 @@ static void doSessionWindowAggImpl(SOperatorInfo* pOperator, SSWindowOperatorInf
   SQueryRuntimeEnv* pRuntimeEnv = pOperator->pRuntimeEnv;
   STableQueryInfo*  item = pRuntimeEnv->current;
 
+  SQueryAttr *pQueryAttr = pRuntimeEnv->pQueryAttr;
+  bool ascQuery = QUERY_IS_ASC_QUERY(pQueryAttr);
+
   // primary timestamp column
   SColumnInfoData* pColInfoData = taosArrayGet(pSDataBlock->pDataBlock, 0);
 
@@ -1783,7 +1786,9 @@ static void doSessionWindowAggImpl(SOperatorInfo* pOperator, SSWindowOperatorInf
         longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
       }
 
-      doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
+      int32_t forwardStep = pInfo->numOfRows;
+      int32_t offset = (ascQuery) ? pInfo->start : pInfo->start + forwardStep - 1;
+      doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, offset, forwardStep, tsList,
                        pSDataBlock->info.rows, pOperator->numOfOutput);
 
       pInfo->curWindow.skey = tsList[j];
@@ -1803,7 +1808,9 @@ static void doSessionWindowAggImpl(SOperatorInfo* pOperator, SSWindowOperatorInf
     longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
   }
 
-  doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
+  int32_t forwardStep = pInfo->numOfRows;
+  int32_t offset = (ascQuery) ? pInfo->start : pInfo->start + forwardStep - 1;
+  doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, offset, forwardStep, tsList,
                    pSDataBlock->info.rows, pOperator->numOfOutput);
 }
 

tests/parallel_test/cases.task

@@ -806,6 +806,7 @@
 3,,develop-test,python3 ./test.py -f 2-query/ts_shortcut.py
 3,,develop-test,python3 ./test.py -f 2-query/nchar_funcs.py
 3,,develop-test,python3 ./test.py -f 2-query/TD-5902.py
+3,,develop-test,python3 ./test.py -f 2-query/sample_order_desc.py
 1,,develop-test,python3 ./test.py -f 2-query/TD-14196.py
 3,,script,./test.sh -f general/compute/scalar_str_concat_len.sim
 3,,develop-test,python3 ./test.py -f 2-query/TD-13414.py