HHH-18493 Resolving already initialized collection elements leads to assertion error

Author: beikov

hibernate-core/src/main/java/org/hibernate/sql/results/graph/collection/internal/ArrayInitializer.java

@@ -6,6 +6,7 @@
  */
 package org.hibernate.sql.results.graph.collection.internal;
 
+import java.lang.reflect.Array;
 import java.util.Iterator;
 import java.util.List;
 import java.util.function.BiConsumer;
@@ -131,9 +132,11 @@ protected void resolveInstanceSubInitializers(ImmediateCollectionInitializerData
 		final Initializer<?> initializer = elementAssembler.getInitializer();
 		if ( initializer != null ) {
 			final RowProcessingState rowProcessingState = data.getRowProcessingState();
-			final Iterator iter = getCollectionInstance( data ).elements();
-			while ( iter.hasNext() ) {
-				initializer.resolveInstance( iter.next(), rowProcessingState );
+			final Integer index = listIndexAssembler.assemble( rowProcessingState );
+			if ( index != null ) {
+				final PersistentArrayHolder<?> arrayHolder = getCollectionInstance( data );
+				assert arrayHolder != null;
+				initializer.resolveInstance( Array.get( arrayHolder.getArray(), index ), rowProcessingState );
 			}
 		}
 	}

hibernate-core/src/main/java/org/hibernate/sql/results/graph/collection/internal/BagInitializer.java

@@ -123,19 +123,7 @@ protected void initializeSubInstancesFromParent(ImmediateCollectionInitializerDa
 	protected void resolveInstanceSubInitializers(ImmediateCollectionInitializerData data) {
 		final Initializer<?> initializer = elementAssembler.getInitializer();
 		if ( initializer != null ) {
-			final RowProcessingState rowProcessingState = data.getRowProcessingState();
-			final PersistentCollection<?> persistentCollection = getCollectionInstance( data );
-			assert persistentCollection != null;
-			if ( persistentCollection instanceof PersistentBag<?> ) {
-				for ( Object element : ( (PersistentBag<?>) persistentCollection ) ) {
-					initializer.resolveInstance( element, rowProcessingState );
-				}
-			}
-			else {
-				for ( Object element : ( (PersistentIdentifierBag<?>) persistentCollection ) ) {
-					initializer.resolveInstance( element, rowProcessingState );
-				}
-			}
+			initializer.resolveKey( data.getRowProcessingState() );
 		}
 	}
 

hibernate-core/src/main/java/org/hibernate/sql/results/graph/collection/internal/ListInitializer.java

@@ -123,10 +123,11 @@ protected void resolveInstanceSubInitializers(ImmediateCollectionInitializerData
 		final Initializer<?> initializer = elementAssembler.getInitializer();
 		if ( initializer != null ) {
 			final RowProcessingState rowProcessingState = data.getRowProcessingState();
-			final PersistentList<?> list = getCollectionInstance( data );
-			assert list != null;
-			for ( Object element : list ) {
-				initializer.resolveInstance( element, rowProcessingState );
+			final Integer index = listIndexAssembler.assemble( rowProcessingState );
+			if ( index != null ) {
+				final PersistentList<?> list = getCollectionInstance( data );
+				assert list != null;
+				initializer.resolveInstance( list.get( index ), rowProcessingState );
 			}
 		}
 	}

hibernate-core/src/main/java/org/hibernate/sql/results/graph/collection/internal/MapInitializer.java

@@ -121,17 +121,27 @@ protected void initializeSubInstancesFromParent(ImmediateCollectionInitializerDa
 	protected void resolveInstanceSubInitializers(ImmediateCollectionInitializerData data) {
 		final Initializer<?> keyInitializer = mapKeyAssembler.getInitializer();
 		final Initializer<?> valueInitializer = mapValueAssembler.getInitializer();
-		if ( keyInitializer != null || valueInitializer != null ) {
-			final RowProcessingState rowProcessingState = data.getRowProcessingState();
-			final PersistentMap<?, ?> map = getCollectionInstance( data );
-			assert map != null;
-			for ( Map.Entry<?, ?> entry : map.entrySet() ) {
-				if ( keyInitializer != null ) {
-					keyInitializer.resolveInstance( entry.getKey(), rowProcessingState );
-				}
-				if ( valueInitializer != null ) {
-					valueInitializer.resolveInstance( entry.getValue(), rowProcessingState );
-				}
+		final RowProcessingState rowProcessingState = data.getRowProcessingState();
+		if ( keyInitializer == null && valueInitializer != null ) {
+			// For now, we only support resolving the value initializer instance when keys have no initializer,
+			// though we could also support map keys with an initializer given that the initialized java type:
+			// * is an entity that uses only the primary key in equals/hashCode.
+			//   If the primary key type is an embeddable, the next condition must hold for that
+			// * or is an embeddable that has no initializers for fields being used in the equals/hashCode
+			//   which violate this same requirement (recursion)
+			final Object key = mapKeyAssembler.assemble( rowProcessingState );
+			if ( key != null ) {
+				final PersistentMap<?, ?> map = getCollectionInstance( data );
+				assert map != null;
+				valueInitializer.resolveInstance( map.get( key ), rowProcessingState );
+			}
+		}
+		else {
+			if ( keyInitializer != null ) {
+				keyInitializer.resolveKey( rowProcessingState );
+			}
+			if ( valueInitializer != null ) {
+				valueInitializer.resolveKey( rowProcessingState );
 			}
 		}
 	}

hibernate-core/src/main/java/org/hibernate/sql/results/graph/collection/internal/SetInitializer.java

@@ -97,12 +97,7 @@ protected void initializeSubInstancesFromParent(ImmediateCollectionInitializerDa
 	protected void resolveInstanceSubInitializers(ImmediateCollectionInitializerData data) {
 		final Initializer<?> initializer = elementAssembler.getInitializer();
 		if ( initializer != null ) {
-			final RowProcessingState rowProcessingState = data.getRowProcessingState();
-			final PersistentSet<?> set = getCollectionInstance( data );
-			assert set != null;
-			for ( Object element : set ) {
-				initializer.resolveInstance( element, rowProcessingState );
-			}
+			initializer.resolveKey( data.getRowProcessingState() );
 		}
 	}