From e76a5077efe64ea3108ff1133339c1ba5d19163f Mon Sep 17 00:00:00 2001
From: Gian Merlino <gianmerlino@gmail.com>
Date: Fri, 17 Jun 2022 16:15:50 -0700
Subject: [PATCH] Fix self-referential shape inspection in
 BaseExpressionColumnValueSelector. (#12669)

* Fix self-referential shape inspection in BaseExpressionColumnValueSelector.

The new test would throw StackOverflowError on the old code.

* Restore prior test.
---
 .../BaseExpressionColumnValueSelector.java    |  2 +-
 .../druid/query/topn/TopNQueryRunnerTest.java | 42 +++++++++++++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/processing/src/main/java/org/apache/druid/segment/virtual/BaseExpressionColumnValueSelector.java b/processing/src/main/java/org/apache/druid/segment/virtual/BaseExpressionColumnValueSelector.java
index 868196c600b..a9fd30a130c 100644
--- a/processing/src/main/java/org/apache/druid/segment/virtual/BaseExpressionColumnValueSelector.java
+++ b/processing/src/main/java/org/apache/druid/segment/virtual/BaseExpressionColumnValueSelector.java
@@ -86,7 +86,7 @@ public abstract class BaseExpressionColumnValueSelector implements ColumnValueSe
   @Override
   public void inspectRuntimeShape(final RuntimeShapeInspector inspector)
   {
-    inspector.visit("rowIdSupplier", this);
+    inspector.visit("rowIdSupplier", rowIdSupplier);
   }
 
   /**
diff --git a/processing/src/test/java/org/apache/druid/query/topn/TopNQueryRunnerTest.java b/processing/src/test/java/org/apache/druid/query/topn/TopNQueryRunnerTest.java
index 2a2f0c68b6d..d475cc9f7f1 100644
--- a/processing/src/test/java/org/apache/druid/query/topn/TopNQueryRunnerTest.java
+++ b/processing/src/test/java/org/apache/druid/query/topn/TopNQueryRunnerTest.java
@@ -4614,6 +4614,48 @@ public class TopNQueryRunnerTest extends InitializedNullHandlingTest
     assertExpectedResults(expectedResults, query);
   }
 
+  @Test
+  public void testFullOnTopNAggregateLongVirtualColumn()
+  {
+    TopNQuery query = new TopNQueryBuilder()
+        .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
+        .granularity(QueryRunnerTestHelper.ALL_GRAN)
+        .virtualColumns(new ExpressionVirtualColumn("v0", "index", ColumnType.LONG, ExprMacroTable.nil()))
+        .dimension(new DefaultDimensionSpec("quality", "quality"))
+        .metric("sumIndex")
+        .threshold(4)
+        .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
+        .aggregators(Collections.singletonList(new LongSumAggregatorFactory("sumIndex", "v0")))
+        .build();
+
+    List<Result<TopNResultValue>> expectedResults = Collections.singletonList(
+        new Result<>(
+            DateTimes.of("2011-01-12T00:00:00.000Z"),
+            new TopNResultValue(
+                Arrays.<Map<String, Object>>asList(
+                    ImmutableMap.<String, Object>builder()
+                                .put("quality", "mezzanine")
+                                .put("sumIndex", 217586L)
+                                .build(),
+                    ImmutableMap.<String, Object>builder()
+                                .put("quality", "premium")
+                                .put("sumIndex", 210722L)
+                                .build(),
+                    ImmutableMap.<String, Object>builder()
+                                .put("quality", "automotive")
+                                .put("sumIndex", 12226L)
+                                .build(),
+                    ImmutableMap.<String, Object>builder()
+                                .put("quality", "entertainment")
+                                .put("sumIndex", 12038L)
+                                .build()
+                )
+            )
+        )
+    );
+    assertExpectedResults(expectedResults, query);
+  }
+
   @Test
   public void testTopNStringVirtualColumn()
   {