Spring Code generation for constructor arguments must cast null indexed argument value

Now that #31495 has been resolved, loading the AOT-optimized ApplicationContext for Spr9799XmlConfigTests fails with the following cause.

 java.lang.IllegalArgumentException: ValueHolder must not be null
    at org.springframework.util.Assert.notNull(Assert.java:172) ~[?:?]
    at org.springframework.beans.factory.config.ConstructorArgumentValues.addIndexedArgumentValue(ConstructorArgumentValues.java:111) ~[?:?]
    at org.springframework.web.servlet.handler.MappedInterceptor__TestContext001_BeanDefinitions.getMappedInterceptorBeanDefinition(MappedInterceptor__TestContext001_BeanDefinitions.java:27) ~[?:?]
    at org.springframework.test.context.junit4.spr9799.Spr9799XmlConfigTests__TestContext001_BeanFactoryRegistrations.registerBeanDefinitions(Spr9799XmlConfigTests__TestContext001_BeanFactoryRegistrations.java:57) ~[?:?]
    at org.springframework.test.context.junit4.spr9799.Spr9799XmlConfigTests__TestContext001_ApplicationContextInitializer.initialize(Spr9799XmlConfigTests__TestContext001_ApplicationContextInitializer.java:19) ~[?:?]
    at org.springframework.test.context.junit4.spr9799.Spr9799XmlConfigTests__TestContext001_ApplicationContextInitializer.initialize(Spr9799XmlConfigTests__TestContext001_ApplicationContextInitializer.java:13) ~[?:?]
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContextForAotRuntime(AbstractGenericContextLoader.java:170) ~[main/:?]
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContextForAotRuntime(AbstractGenericContextLoader.java:1) ~[main/:?]
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContextForAotRuntime(AbstractDelegatingSmartContextLoader.java:263) ~[main/:?]
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInAotMode(DefaultCacheAwareContextLoaderDelegate.java:255) ~[main/:?]
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:149) ~[main/:?]

Generated Code:

package org.springframework.web.servlet.handler;

import java.lang.String;
import org.springframework.beans.factory.aot.BeanInstanceSupplier;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.web.servlet.HandlerInterceptor;

/**
 * Bean definitions for {@link MappedInterceptor}.
 */
public class MappedInterceptor__TestContext001_BeanDefinitions {

  // other methods

  /**
   * Get the bean definition for 'mappedInterceptor#0'.
   */
  public static BeanDefinition getMappedInterceptorBeanDefinition() {
    RootBeanDefinition beanDefinition = new RootBeanDefinition(MappedInterceptor.class);
    beanDefinition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
    beanDefinition.getConstructorArgumentValues().addIndexedArgumentValue(0, null);
    beanDefinition.getConstructorArgumentValues().addIndexedArgumentValue(1, ConversionServiceExposingInterceptor__TestContext001_BeanDefinitions.getMappedInterceptorInnerBeanBeanDefinition());
    beanDefinition.setInstanceSupplier(getMappedInterceptorInstanceSupplier());
    return beanDefinition;
  }
}

This line is the source of the exception:

beanDefinition.getConstructorArgumentValues().addIndexedArgumentValue(0, null);

Since addIndexedArgumentValue(...) is overloaded, the compiler picks the variant that accepts a ValueHolder when the second argument is null, and that variant has a notNull check for the ValueHolder.

Updating the code generator so that it generates the following seems to be one way to address this issue.

beanDefinition.getConstructorArgumentValues().addIndexedArgumentValue(0, (Object) null);

Comment From: snicoll

Those damn overloaded methods.