SpringBoot ConfigDataLocationResolvers.ConfigDataLocationResolvers(..., ResourceLoader resourceLoader) does not use a resourceLoader to load factory names

org.springframework.boot.context.config.ConfigDataLocationResolvers.ConfigDataLocationResolvers(
    DeferredLogFactory logFactory, 
    ConfigurableBootstrapContext bootstrapContext, 
    Binder binder, 
    ResourceLoader resourceLoader) {
        this(
            logFactory, 
            bootstrapContext, 
            binder, 
            resourceLoader, 
            SpringFactoriesLoader.loadFactoryNames(
                ConfigDataLocationResolver.class, 
                (ClassLoader)null // !!! <= Here should be:  resourceLoader == null 
                                           // !!!                                     ? (ClassLoader)null 
                                           // !!!                                     :  resourceLoader.getClassLoader()
            )
        );
    }

Otherwise the following exception occurred here:

ConfigDataEnvironment.ConfigDataEnvironment(..., ConfigDataEnvironmentUpdateListener environmentUpdateListener) {
    ...
    this.resolvers = createConfigDataLocationResolvers(logFactory, bootstrapContext, binder, resourceLoader);
    ...
}

ConfigDataLocationResolvers::

    List<ConfigDataResolutionResult> resolve(ConfigDataLocationResolverContext context, ConfigDataLocation location,
            Profiles profiles) {
        if (location == null) {
            return Collections.emptyList();
        }
        for (ConfigDataLocationResolver<?> resolver : getResolvers()) {
            if (resolver.isResolvable(context, location)) {
                return resolve(resolver, context, location, profiles);
            }
        }
        throw new UnsupportedConfigDataLocationException(location); // !!! <= Here
    }

Stack trace:

    Caused by: org.springframework.boot.context.config.UnsupportedConfigDataLocationException: Unsupported config data location 'optional:classpath:/application-prod.properties'
    at org.springframework.boot.context.config.ConfigDataLocationResolvers.resolve(ConfigDataLocationResolvers.java:110)
    at org.springframework.boot.context.config.ConfigDataImporter.resolve(ConfigDataImporter.java:101)
    at org.springframework.boot.context.config.ConfigDataImporter.resolve(ConfigDataImporter.java:93)
    at org.springframework.boot.context.config.ConfigDataImporter.resolveAndLoad(ConfigDataImporter.java:81)
    at org.springframework.boot.context.config.ConfigDataEnvironmentContributors.withProcessedImports(ConfigDataEnvironmentContributors.java:121)
    at org.springframework.boot.context.config.ConfigDataEnvironment.processInitial(ConfigDataEnvironment.java:242)
    at org.springframework.boot.context.config.ConfigDataEnvironment.processAndApply(ConfigDataEnvironment.java:230)
    at org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessor.postProcessEnvironment(ConfigDataEnvironmentPostProcessor.java:97)
    at org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessor.postProcessEnvironment(ConfigDataEnvironmentPostProcessor.java:89)
    at org.springframework.boot.env.EnvironmentPostProcessorApplicationListener.onApplicationEnvironmentPreparedEvent(EnvironmentPostProcessorApplicationListener.java:100)
    at org.springframework.boot.env.EnvironmentPostProcessorApplicationListener.onApplicationEvent(EnvironmentPostProcessorApplicationListener.java:86)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:131)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:82)
    at org.springframework.boot.SpringApplicationRunListeners.lambda$environmentPrepared$2(SpringApplicationRunListeners.java:63)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:117)
    at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:111)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:62)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:362)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:123)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)

Comment From: wilkinsona

Thanks for the report. This is a duplicate of #26149.