From 1905e8bba32c0198bdf4b5002e2bb7561504789d Mon Sep 17 00:00:00 2001
From: Andrea Boriero <andrea@hibernate.org>
Date: Mon, 8 Mar 2021 19:10:26 +0100
Subject: [PATCH] HHH-14482 Do not discard prior implicit join by key

---
 .../query/hql/internal/DomainPathPart.java    |  6 +++++
 .../sqm/tree/domain/AbstractSqmPath.java      | 14 ++++++++--
 .../query/sqm/tree/domain/SqmPath.java        |  2 ++
 .../SubQueryImplicitJoinReferenceTest.java    | 27 ++++++++++++++++---
 4 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/query/hql/internal/DomainPathPart.java b/hibernate-core/src/main/java/org/hibernate/query/hql/internal/DomainPathPart.java
index 48ce90fefa..52c1a05eb7 100644
--- a/hibernate-core/src/main/java/org/hibernate/query/hql/internal/DomainPathPart.java
+++ b/hibernate-core/src/main/java/org/hibernate/query/hql/internal/DomainPathPart.java
@@ -45,6 +45,12 @@ public class DomainPathPart implements SemanticPathPart {
 			throw new SemanticException( "Cannot resolve path (`" + name + "`) relative to `"  + lhs.getNavigablePath() + "`" );
 		}
 		//noinspection unchecked
+		final SqmPath<?> existingImplicitJoinPath = lhs.getImplicitJoinPath( name );
+		if ( existingImplicitJoinPath != null ) {
+			currentPath = existingImplicitJoinPath;
+			return this;
+		}
+
 		currentPath = subPathSource.createSqmPath( lhs, creationState );
 		if ( isTerminal ) {
 			return currentPath;
diff --git a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/AbstractSqmPath.java b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/AbstractSqmPath.java
index 3ccbd645e8..3a941c48fe 100644
--- a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/AbstractSqmPath.java
+++ b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/AbstractSqmPath.java
@@ -125,11 +125,21 @@ public abstract class AbstractSqmPath<T> extends AbstractSqmExpression<T> implem
 		}
 
 		final String relativeName = path.getNavigablePath().getLocalName();
-		if ( !implicitJoinPaths.containsKey( relativeName ) ) {
-			implicitJoinPaths.put( relativeName, path );
+
+		final SqmPath<?> previous = implicitJoinPaths.put( relativeName, path );
+		if ( previous != null && previous != path ) {
+			throw new IllegalStateException( "Implicit-join path registration unexpectedly overrode previous registration - " + relativeName );
 		}
 	}
 
+	@Override
+	public SqmPath<?> getImplicitJoinPath(String name) {
+		if ( implicitJoinPaths == null ) {
+			return null;
+		}
+		return implicitJoinPaths.get( name );
+	}
+
 	@Override
 	public String getExplicitAlias() {
 		return getAlias();
diff --git a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/SqmPath.java b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/SqmPath.java
index 1f7ed1f8eb..eccd2f1c2b 100644
--- a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/SqmPath.java
+++ b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/domain/SqmPath.java
@@ -77,6 +77,8 @@ public interface SqmPath<T> extends SqmExpression<T>, SemanticPathPart, JpaPath<
 	 */
 	void registerImplicitJoinPath(SqmPath<?> path);
 
+	SqmPath<?> getImplicitJoinPath(String name);
+
 	/**
 	 * This node's type is its "referenced path source"
 	 */
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/query/sqm/exec/SubQueryImplicitJoinReferenceTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/query/sqm/exec/SubQueryImplicitJoinReferenceTest.java
index 3d4a551cb6..62a731ff97 100644
--- a/hibernate-core/src/test/java/org/hibernate/orm/test/query/sqm/exec/SubQueryImplicitJoinReferenceTest.java
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/query/sqm/exec/SubQueryImplicitJoinReferenceTest.java
@@ -54,14 +54,35 @@ public class SubQueryImplicitJoinReferenceTest {
     public void performHqlTest(SessionFactoryScope scope) {
         // Now simulate running an audit query
         scope.inSession( session -> {
-            session.createQuery( "select e__ FROM org.hibernate.orm.test.SubQueryImplicitJoinReferenceTest$TheEntity e__ "
+            session.createQuery( "select e__ FROM TheEntity e__ "
                                          + "WHERE e__.originalId.rev.id = (select max(e2__.originalId.rev.id) FROM "
-                                         + "org.hibernate.orm.test.SubQueryImplicitJoinReferenceTest$TheEntity e2__ WHERE " +
+                                         + "TheEntity e2__ WHERE " +
                                          "e2__.originalId.rev.id <= 2 and e__.originalId.id = e2__.originalId.id)" ).list();
         } );
     }
 
-    @Entity
+    @Test
+    public void performHqlTest2(SessionFactoryScope scope) {
+        // Now simulate running an audit query
+        scope.inSession( session -> {
+            session.createQuery( "select e__ FROM TheEntity e__ "
+                                         + "WHERE e__.originalId.id = (select max(e2__.originalId.id) FROM "
+                                         + "TheEntity e2__ WHERE " +
+                                         "e__.originalId.id = e2__.originalId.id and e2__.originalId.rev.id <= 2)" ).list();
+        } );
+    }
+
+    @Test
+    public void performHqlTest3(SessionFactoryScope scope) {
+        // Now simulate running an audit query
+        scope.inSession( session -> {
+            session.createQuery( "select e2__.originalId.id, e2__.originalId.rev.id  FROM "
+                                         + "TheEntity e2__ WHERE " +
+                                         " e2__.originalId.rev.id <= 2" ).list();
+        } );
+    }
+
+    @Entity(name = "TheEntity")
     public static class TheEntity {
         @EmbeddedId
         private OriginalId originalId;