GenericTypeResolver properly handles bound parameterized type

Issue: SPR-10819
(cherry picked from commit ea6525f1)

spring-core/src/main/java/org/springframework/core/GenericTypeResolver.java

@@ -305,7 +305,7 @@ public abstract class GenericTypeResolver {
 	}
 
 	/**
-	 * Extract a class instance from given Type.
+	 * Extract a Class from the given Type.
 	 */
 	private static Class<?> extractClass(Class<?> ownerClass, Type arg) {
 		if (arg instanceof ParameterizedType) {
@@ -322,9 +322,12 @@ public abstract class GenericTypeResolver {
 			arg = getTypeVariableMap(ownerClass).get(tv);
 			if (arg == null) {
 				arg = extractBoundForTypeVariable(tv);
+				if (arg instanceof ParameterizedType) {
+					return extractClass(ownerClass, ((ParameterizedType) arg).getRawType());
+				}
 			}
 			else {
-				arg = extractClass(ownerClass, arg);
+				return extractClass(ownerClass, arg);
 			}
 		}
 		return (arg instanceof Class ? (Class) arg : Object.class);

spring-core/src/test/java/org/springframework/core/GenericTypeResolverTests.java

@@ -19,7 +19,6 @@ package org.springframework.core;
 import java.lang.reflect.Method;
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
-
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
@@ -27,7 +26,6 @@ import java.util.Map;
 import org.junit.Test;
 
 import static org.junit.Assert.*;
-
 import static org.springframework.core.GenericTypeResolver.*;
 import static org.springframework.util.ReflectionUtils.*;
 
@@ -76,7 +74,6 @@ public class GenericTypeResolverTests {
 	 */
 	@Test
 	public void genericMethodReturnTypes() {
-
 		Method notParameterized = findMethod(MyTypeWithMethods.class, "notParameterized", new Class[] {});
 		assertEquals(String.class, resolveReturnTypeForGenericMethod(notParameterized, new Object[] {}));
 
@@ -151,6 +148,11 @@ public class GenericTypeResolverTests {
 			assertEquals(Integer[].class, resolveType(genericArrMessageMethodParam.getGenericParameterType(), varMap));
 	}
 
+	@Test
+	public void testBoundParameterizedType() {
+		assertEquals(B.class, resolveTypeArgument(TestImpl.class, ITest.class));
+	}
+
 
 	public interface MyInterfaceType<T> {
 	}
@@ -250,4 +252,13 @@ public class GenericTypeResolverTests {
 	static class GenericClass<T> {
 	}
 
+	class A{}
+
+	class B<T>{}
+
+	class ITest<T>{}
+
+	class TestImpl<I extends A, T extends B<I>> extends ITest<T>{
+	}
+
 }