HSEARCH-5358 Fail faster if an enclosing instance parameter is encountered in a projection constructor on JDK 25+

see https://bugs.openjdk.org/browse/JDK-8164714

Author: marko-bekhta

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/logging/impl/PojoMapperLog.java

@@ -55,7 +55,7 @@ public interface PojoMapperLog
 	 * here to the next value.
 	 */
 	@LogMessage(level = TRACE)
-	@Message(id = ID_OFFSET + 179, value = "")
+	@Message(id = ID_OFFSET + 180, value = "")
 	void nextLoggerIdForConvenience();
 
 }

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/logging/impl/ProjectionLog.java

@@ -162,4 +162,9 @@ SearchException invalidParameterTypeForDistanceProjectionInProjectionConstructor
 	SearchException cannotBindSortedSetWithNonComparableElements(@FormatWith(ClassFormatter.class) Class<?> elementType,
 			@Param EventContext eventContext);
 
+	@Message(id = ID_OFFSET + 179,
+			value = "An enclosing instance constructor parameter on a projection constructor is not allowed. " +
+					"Make the projection class either static, or a top-level class to remove the enclosing instance constructor parameter.")
+	SearchException nullEnclosingParameterInProjectionConstructorNotAllowed(@Param EventContext eventContext);
+
 }

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/model/spi/PojoMethodParameterModel.java

@@ -9,6 +9,7 @@
 import java.util.stream.Stream;
 
 import org.hibernate.search.engine.mapper.model.spi.MappableTypeModel;
+import org.hibernate.search.util.common.annotation.Incubating;
 
 public interface PojoMethodParameterModel<T> {
 
@@ -26,6 +27,17 @@ public interface PojoMethodParameterModel<T> {
 	 */
 	boolean isEnclosingInstance();
 
+	/**
+	 * Starting with JDk 25, there is an additional check within the constructor itself,
+	 * that by default prevents passing {@code null} as a value for an enclosing instance.
+	 *
+	 * @return Whether {@code null} can be passed as an enclosing instance.
+	 */
+	@Incubating
+	default boolean enclosingInstanceCanBeNull() {
+		return Runtime.version().feature() < 25;
+	}
+
 	/**
 	 * @return {@code true} if {@code obj} is a {@link MappableTypeModel} referencing the exact same type
 	 * with the exact same exposed metadata.

mapper/pojo-base/src/main/java/org/hibernate/search/mapper/pojo/search/definition/binding/impl/ProjectionConstructorParameterBinder.java

@@ -56,7 +56,16 @@ BeanHolder<? extends ProjectionDefinition<?>> bind() {
 			// and it's often useful to be able to declare a method-local type for projections
 			// (those types have a "surrounding instance" parameter in their constructor
 			// even if they don't use it).
-			return ConstantProjectionDefinition.nullValue();
+
+			// NOTE: with JDK 25+ this is no longer the case,
+			// and will fail further at runtime when such projection is created.
+			// Hence, let's fails faster instead;
+			if ( parameter.enclosingInstanceCanBeNull() ) {
+				return ConstantProjectionDefinition.nullValue();
+			}
+			else {
+				throw ProjectionLog.INSTANCE.nullEnclosingParameterInProjectionConstructorNotAllowed( eventContext() );
+			}
 		}
 
 		BeanHolder<? extends ProjectionDefinition<?>> result = null;