[670] Do not recursively check the upper bound type if it matches the…

src/main/java/org/eclipse/yasson/internal/ReflectionUtils.java

@@ -252,7 +252,7 @@ public static Type resolveTypeArguments(ParameterizedType typeToResolve, Type ty
                     }
                 }
 
-                if (resolvedArgs[i] == null) {
+                if (resolvedArgs[i] == null || resolvedArgs[i].equals(typeToResolve)) {
                     if (typeToSearch instanceof Class) {
                         return Object.class;
                     }

src/test/java/org/eclipse/yasson/defaultmapping/generics/GenericsTest.java

@@ -12,13 +12,19 @@
 
 package org.eclipse.yasson.defaultmapping.generics;
 
+import static org.eclipse.yasson.Jsonbs.defaultJsonb;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.lang.reflect.Field;
 import java.lang.reflect.Type;
-import java.lang.reflect.WildcardType;
 import java.math.BigDecimal;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
@@ -30,8 +36,6 @@
 import jakarta.json.bind.Jsonb;
 import jakarta.json.bind.JsonbBuilder;
 import jakarta.json.bind.JsonbConfig;
-import java.lang.reflect.Field;
-import java.util.Collection;
 import org.eclipse.yasson.TestTypeToken;
 import org.eclipse.yasson.adapters.model.GenericBox;
 import org.eclipse.yasson.defaultmapping.generics.model.AnotherGenericTestClass;
@@ -48,24 +52,21 @@
 import org.eclipse.yasson.defaultmapping.generics.model.GenericArrayClass;
 import org.eclipse.yasson.defaultmapping.generics.model.GenericTestClass;
 import org.eclipse.yasson.defaultmapping.generics.model.GenericWithUnboundedWildcardClass;
+import org.eclipse.yasson.defaultmapping.generics.model.LowerBoundTypeVariableWithCollectionAttributeClass;
 import org.eclipse.yasson.defaultmapping.generics.model.MultiLevelExtendedGenericTestClass;
 import org.eclipse.yasson.defaultmapping.generics.model.MultipleBoundsContainer;
 import org.eclipse.yasson.defaultmapping.generics.model.MyCyclicGenericClass;
 import org.eclipse.yasson.defaultmapping.generics.model.PropagatedGenericClass;
 import org.eclipse.yasson.defaultmapping.generics.model.Shape;
 import org.eclipse.yasson.defaultmapping.generics.model.StaticCreatorContainer;
+import org.eclipse.yasson.defaultmapping.generics.model.TreeContainer;
+import org.eclipse.yasson.defaultmapping.generics.model.TreeElement;
 import org.eclipse.yasson.defaultmapping.generics.model.WildCardClass;
 import org.eclipse.yasson.defaultmapping.generics.model.WildcardMultipleBoundsClass;
 import org.eclipse.yasson.serializers.model.Box;
 import org.eclipse.yasson.serializers.model.Crate;
 import org.junit.jupiter.api.Test;
 
-import static org.eclipse.yasson.Jsonbs.defaultJsonb;
-import org.eclipse.yasson.defaultmapping.generics.model.LowerBoundTypeVariableWithCollectionAttributeClass;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * This class contains JSONB default mapping generics tests.
  *
@@ -513,6 +514,18 @@ public void wildcardCollectionContainer() {
         final CollectionContainer result = defaultJsonb.fromJson(expectedJson, CollectionContainer.class);
         assertEquals(collectionContainer, result);
     }
+
+    @Test
+    public void genericUpperBoundContainer() {
+        final String expectedJson = "{\"tree\":{\"children\":[{\"children\":[],\"name\":\"child\"}],\"name\":\"parent\"}}";
+        final TreeContainer<TreeElement> container = new TreeContainer<>();
+        final TreeElement parent = new TreeElement("parent");
+        parent.setChildren(List.of(new TreeElement("child")));
+        container.setTree(parent);
+
+        assertEquals(expectedJson, defaultJsonb.toJson(container));
+
+    }
 
     public interface FunctionalInterface<T> {
         T getValue();

src/test/java/org/eclipse/yasson/defaultmapping/generics/model/TreeContainer.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2025 Red Hat, Inc. and/or its affiliates.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.defaultmapping.generics.model;
+
+/**
+ * @author <a href="mailto:[email protected]">James R. Perkins</a>
+ */
+public class TreeContainer<T extends TreeTypeContainer<T>> {
+
+    private TreeTypeContainer<T> tree;
+
+    public TreeTypeContainer<T> getTree() {
+        return tree;
+    }
+
+    public void setTree(final TreeTypeContainer<T> tree) {
+        this.tree = tree;
+    }
+}

src/test/java/org/eclipse/yasson/defaultmapping/generics/model/TreeElement.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2025 Red Hat, Inc. and/or its affiliates.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.defaultmapping.generics.model;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author <a href="mailto:[email protected]">James R. Perkins</a>
+ */
+public class TreeElement implements TreeTypeContainer<TreeElement> {
+
+    private final String name;
+    private List<TreeElement> children = new ArrayList<>();
+
+    public TreeElement(final String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public List<TreeElement> getChildren() {
+        return children;
+    }
+
+    public void setChildren(final List<TreeElement> children) {
+        this.children = children;
+    }
+}

src/test/java/org/eclipse/yasson/defaultmapping/generics/model/TreeTypeContainer.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2025 Red Hat, Inc. and/or its affiliates.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.defaultmapping.generics.model;
+
+import java.util.List;
+
+/**
+ * @author <a href="mailto:[email protected]">James R. Perkins</a>
+ */
+public interface TreeTypeContainer<T extends TreeTypeContainer<T>> {
+
+    List<T> getChildren();
+
+    void setChildren(List<T> children);
+}