From 48bb798d0dcc039997f83f44424cb40dfeb4d292 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Osipiuk?= <lukasz@osipiuk.net>
Date: Fri, 16 Sep 2022 19:56:13 +0200
Subject: [PATCH] Make PartitionedOutputOperator.finish() idempotent

The PartitionedOutputOperator.finish() was not idempotent in the
case when only position counter was tracked in
PositionsAppenderPageBuilder. This could result in wrong query results.
---
 .../trino/operator/output/PositionsAppenderPageBuilder.java   | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/core/trino-main/src/main/java/io/trino/operator/output/PositionsAppenderPageBuilder.java b/core/trino-main/src/main/java/io/trino/operator/output/PositionsAppenderPageBuilder.java
index 7c232be59797..f90db9682c26 100644
--- a/core/trino-main/src/main/java/io/trino/operator/output/PositionsAppenderPageBuilder.java
+++ b/core/trino-main/src/main/java/io/trino/operator/output/PositionsAppenderPageBuilder.java
@@ -98,10 +98,6 @@ public boolean isEmpty()
 
     public Page build()
     {
-        if (channelAppenders.length == 0) {
-            return new Page(declaredPositions);
-        }
-
         Block[] blocks = new Block[channelAppenders.length];
         for (int i = 0; i < blocks.length; i++) {
             blocks[i] = channelAppenders[i].build();