HSEARCH-4845 Use a different field for retrieving a root object id in…

… the Lucene backend

- Temporary use a change until this is addressed in main

(cherry picked from commit f646ae1)

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/document/impl/LuceneRootDocumentBuilder.java

@@ -42,7 +42,8 @@ private List<Document> assembleDocuments(MultiTenancyStrategy multiTenancyStrate
 		// We own the document content, so we finalize it ourselves.
 		Document document = documentContent.finalizeDocument( multiTenancyStrategy, tenantId, routingKey );
 		document.add( MetadataFields.searchableMetadataField( MetadataFields.typeFieldName(), MetadataFields.TYPE_MAIN_DOCUMENT ) );
-		document.add( MetadataFields.searchableRetrievableMetadataField( MetadataFields.idFieldName(), id ) );
+		document.add( MetadataFields.searchableMetadataField( MetadataFields.idFieldName(), id ) );
+		document.add( MetadataFields.retrievableMetadataField( MetadataFields.idDocValueFieldName(), id ) );
 
 		// In the list of documents, a child must appear before its parent,
 		// so we let children contribute their document first.

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/lowlevel/collector/impl/DocumentReferenceValues.java

@@ -40,7 +40,7 @@ protected DocumentReferenceValues(CollectorExecutionContext executionContext) {
 	@Override
 	public final void context(LeafReaderContext context) throws IOException {
 		this.currentLeafMappedTypeName = metadataResolver.resolveMappedTypeName( context );
-		this.currentLeafIdDocValues = DocValues.getBinary( context.reader(), MetadataFields.idFieldName() );
+		this.currentLeafIdDocValues = DocValues.getBinary( context.reader(), MetadataFields.idDocValueFieldName() );
 	}
 
 	@Override

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/lowlevel/collector/impl/IdentifierValues.java

@@ -20,7 +20,7 @@ public final class IdentifierValues implements Values<String> {
 
 	@Override
 	public void context(LeafReaderContext context) throws IOException {
-		this.currentLeafIdDocValues = DocValues.getBinary( context.reader(), MetadataFields.idFieldName() );
+		this.currentLeafIdDocValues = DocValues.getBinary( context.reader(), MetadataFields.idDocValueFieldName() );
 	}
 
 	@Override

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/lowlevel/common/impl/MetadataFields.java

@@ -16,26 +16,28 @@
 public class MetadataFields {
 
 	private static final FieldType METADATA_FIELD_TYPE_WITH_INDEX;
-	private static final FieldType METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES;
+	private static final FieldType METADATA_FIELD_TYPE_WITH_DOCVALUES;
 	static {
 		METADATA_FIELD_TYPE_WITH_INDEX = new FieldType();
 		METADATA_FIELD_TYPE_WITH_INDEX.setTokenized( false );
 		METADATA_FIELD_TYPE_WITH_INDEX.setOmitNorms( true );
 		METADATA_FIELD_TYPE_WITH_INDEX.setIndexOptions( IndexOptions.DOCS );
 		METADATA_FIELD_TYPE_WITH_INDEX.freeze();
 
-		METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES = new FieldType();
-		METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES.setTokenized( false );
-		METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES.setOmitNorms( true );
-		METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES.setIndexOptions( IndexOptions.DOCS );
-		METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES.setDocValuesType( DocValuesType.BINARY );
-		METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES.freeze();
+		METADATA_FIELD_TYPE_WITH_DOCVALUES = new FieldType();
+		METADATA_FIELD_TYPE_WITH_DOCVALUES.setTokenized( false );
+		METADATA_FIELD_TYPE_WITH_DOCVALUES.setOmitNorms( true );
+		METADATA_FIELD_TYPE_WITH_DOCVALUES.setIndexOptions( IndexOptions.NONE );
+		METADATA_FIELD_TYPE_WITH_DOCVALUES.setDocValuesType( DocValuesType.BINARY );
+		METADATA_FIELD_TYPE_WITH_DOCVALUES.freeze();
 	}
 
 	private static final String INTERNAL_FIELD_PREFIX = "__HSEARCH_";
 
 	private static final String ID_FIELD_NAME = internalFieldName( "id" );
 
+	private static final String ID_DOCVALUE_FIELD_NAME = internalFieldName( "id_docvalue" );
+
 	private static final String ROUTING_KEY_FIELD_NAME = internalFieldName( "routing_key" );
 
 	private static final String TENANT_ID_FIELD_NAME = internalFieldName( "tenantId" );
@@ -64,14 +66,18 @@ public static IndexableField searchableMetadataField(String name, String value)
 		return new Field( name, value, METADATA_FIELD_TYPE_WITH_INDEX );
 	}
 
-	public static IndexableField searchableRetrievableMetadataField(String name, String value) {
-		return new Field( name, new BytesRef( value ), METADATA_FIELD_TYPE_WITH_INDEX_WITH_DOCVALUES );
+	public static IndexableField retrievableMetadataField(String name, String value) {
+		return new Field( name, new BytesRef( value ), METADATA_FIELD_TYPE_WITH_DOCVALUES );
 	}
 
 	public static String idFieldName() {
 		return ID_FIELD_NAME;
 	}
 
+	public static String idDocValueFieldName() {
+		return ID_DOCVALUE_FIELD_NAME;
+	}
+
 	public static String routingKeyFieldName() {
 		return ROUTING_KEY_FIELD_NAME;
 	}

documentation/src/main/asciidoc/migration/index.asciidoc

@@ -43,9 +43,13 @@ Hibernate Search's requirements did not change in version {hibernateSearchVersio
 [[data-format]]
 == Data format and schema changes
 
-Indexes created with Hibernate Search {hibernateSearchPreviousStableVersionShort}
+Elasticsearch indexes created with Hibernate Search {hibernateSearchPreviousStableVersionShort}
 can be read from and written to with Hibernate Search {hibernateSearchVersion}.
 
+Reading and writing to Lucene indexes created with Hibernate Search {hibernateSearchPreviousStableVersionShort}
+using Hibernate Search {hibernateSearchVersion} may lead to exceptions, since there were incompatible changes applied to internal fields.
+You must recreate your Lucene indexes and reindex your database. The easiest way to do so is to use link:{hibernateSearchDocUrl}#indexing-massindexer[the `MassIndexer`] with link:{hibernateSearchDocUrl}#indexing-massindexer-parameters-drop-and-create-schema[`dropAndCreateSchemaOnStart(true)`].
+
 If your Hibernate Search mapping includes `GeoPoint` fields that are using the default value for the `projectable` option,
 and are using either the default value or `Sortable.NO` for the `sortable` option, Elasticsearch schema validation
 will fail on startup because of missing docvalues on those fields.