TYPO3 Core

In the function \TYPO3\ClassAliasLoader\ClassAliasLoader::loadOriginalClassAndSetAliases() should be test $this->aliasMap['classNameToAliasMapping'][$originalClassName] with isset() and is_array().

In normal Case is $this->aliasMap['classNameToAliasMapping'][$originalClassName] === null and it will be log the foloow Error:
PHP Warning: Invalid argument supplied for foreach() in vendor/typo3/class-alias-loader/src/ClassAliasLoader.php line 175

original Code:

    /**
     * Load classes and set aliases.
     * The class_exists calls are safety guards to avoid fatals when
     * class files were included or aliases were set manually in userland code.
     *
     * @param string $originalClassName
     * @return bool|null
     */
    protected function loadOriginalClassAndSetAliases($originalClassName)
    {
        if ($this->classOrInterfaceExists($originalClassName) || $this->loadClass($originalClassName)) {
                foreach ($this->aliasMap['classNameToAliasMapping'][$originalClassName] as $aliasClassName) {
                    if (!$this->classOrInterfaceExists($aliasClassName)) {
                        class_alias($originalClassName, $aliasClassName);
                    }
                }
            return true;
        } else {
            //dump('else', $originalClassName);
        }
        //dump($originalClassName,$this->aliasMap,$this->aliasMap['classNameToAliasMapping'][$originalClassName]);
        return null;
    }

better Code version:

    /**
     * Load classes and set aliases.
     * The class_exists calls are safety guards to avoid fatals when
     * class files were included or aliases were set manually in userland code.
     *
     * @param string $originalClassName
     * @return bool|null
     */
    protected function loadOriginalClassAndSetAliases($originalClassName)
    {
        if ($this->classOrInterfaceExists($originalClassName) || $this->loadClass($originalClassName)) {
            if(isset($this->aliasMap['classNameToAliasMapping'][$originalClassName]) && is_array($this->aliasMap['classNameToAliasMapping'][$originalClassName])) {
                foreach ($this->aliasMap['classNameToAliasMapping'][$originalClassName] as $aliasClassName) {
                    if (!$this->classOrInterfaceExists($aliasClassName)) {
                        class_alias($originalClassName, $aliasClassName);
                    }
                }
            }
            return true;
        } else {
            //dump('else', $originalClassName);
        }
        //dump($originalClassName,$this->aliasMap,$this->aliasMap['classNameToAliasMapping'][$originalClassName]);
        return null;
    }

Here the fisrt entries of my $this->aliasMap

^ array:2 [▼
  "aliasToClassNameMapping" => []
  "classNameToAliasMapping" => array:3623 [▼
    "TYPO3\ClassAliasLoader\ClassAliasMap" => null
    "TYPO3\CMS\Core\Core\SystemEnvironmentBuilder" => null
    "TYPO3\CMS\Core\Utility\GeneralUtility" => null
    "TYPO3\CMS\Core\Core\Environment" => null
    "TYPO3\CMS\Core\Utility\PathUtility" => null
    "TYPO3\CMS\Core\Core\ApplicationContext" => null
    "Symfony\Polyfill\Php80\Php80" => null
    "TYPO3\CMS\Core\Core\Bootstrap" => null
    "TYPO3\CMS\Core\Core\RequestId" => null
    "TYPO3\CMS\Core\Utility\StringUtility" => null
    "TYPO3\CMS\Core\Core\ClassLoadingInformation" => null
    "Doctrine\Common\Annotations\AnnotationRegistry" => null
    "Doctrine\Common\Annotations\AnnotationReader" => null
    "Doctrine\Common\Annotations\Reader" => null
    "Doctrine\Common\Annotations\ImplicitlyIgnoredAnnotationNames" => null
    "TYPO3\CMS\Core\Configuration\ConfigurationManager" => null
    "TYPO3\CMS\Core\LinkHandling\LinkHandlingInterface" => null
    "TYPO3\CMS\Core\Log\LogLevel" => null
    "Psr\Log\LogLevel" => null
    "TYPO3\CMS\Core\Utility\ArrayUtility" => null
    "TYPO3\CMS\Core\Log\LogManager" => null
    "TYPO3\CMS\Core\SingletonInterface" => null
    "TYPO3\CMS\Core\Log\LogManagerInterface" => null
    "TYPO3\CMS\Core\Log\Logger" => null
    "Psr\Log\AbstractLogger" => null
    "Psr\Log\LoggerInterface" => null
    "TYPO3\CMS\Core\Error\ErrorHandler" => null
    "TYPO3\CMS\Core\Error\ErrorHandlerInterface" => null
    "Psr\Log\LoggerAwareInterface" => null
    "Psr\Log\LoggerAwareTrait" => null
    "TYPO3\CMS\Core\Log\Writer\FileWriter" => null
    "TYPO3\CMS\Core\Log\Writer\AbstractWriter" => null
    "TYPO3\CMS\Core\Log\Writer\WriterInterface" => null
    "TYPO3\CMS\Core\Security\BlockSerializationTrait" => null
    "TYPO3\CMS\Core\Error\DebugExceptionHandler" => null
    "TYPO3\CMS\Core\Error\AbstractExceptionHandler" => null
    "TYPO3\CMS\Core\Error\ExceptionHandlerInterface" => null
    "TYPO3\PharStreamWrapper\Manager" => null
    "TYPO3\PharStreamWrapper\Behavior" => null
    "TYPO3\PharStreamWrapper\Assertable" => null
    "TYPO3\PharStreamWrapper\Interceptor\ConjunctionInterceptor" => null
    "TYPO3\CMS\Core\IO\PharStreamWrapperInterceptor" => null
    "TYPO3\PharStreamWrapper\Interceptor\PharMetaDataInterceptor" => null
    "TYPO3\PharStreamWrapper\Resolver\PharInvocationCollection" => null
    "TYPO3\PharStreamWrapper\Collectable" => null
    "TYPO3\PharStreamWrapper\Resolver\PharInvocationResolver" => null
    "TYPO3\PharStreamWrapper\Resolvable" => null
    "TYPO3\PharStreamWrapper\PharStreamWrapper" => null
    "TYPO3\CMS\Core\Cache\Backend\NullBackend" => null
    "TYPO3\CMS\Core\Cache\Backend\AbstractBackend" => null
    "TYPO3\CMS\Core\Cache\Backend\BackendInterface" => null
    "TYPO3\CMS\Core\Cache\Backend\PhpCapableBackendInterface" => null
    "TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface" => null
    "TYPO3\CMS\Core\Cache\Frontend\PhpFrontend" => null
    "TYPO3\CMS\Core\Cache\Frontend\AbstractFrontend" => null
    "TYPO3\CMS\Core\Cache\Frontend\FrontendInterface" => null
    "TYPO3\CMS\Core\Package\Cache\PackageStatesPackageCache" => null
    "TYPO3\CMS\Core\Package\Cache\PackageCacheInterface" => null
    "TYPO3\CMS\Core\Service\DependencyOrderingService" => null
    "TYPO3\CMS\Core\Package\PackageManager" => null
    "TYPO3\CMS\Core\Information\Typo3Version" => null
    "TYPO3\CMS\Core\Package\Cache\PackageCacheEntry" => null
    "TYPO3\CMS\Core\Package\Exception\PackageStatesUnavailableException" => null
    "TYPO3\CMS\Core\Package\Exception" => null
    "TYPO3\CMS\Core\Exception" => null
    "TYPO3\CMS\Core\Package\Exception\PackageManagerCacheUnavailableException" => null
    "TYPO3\CMS\Core\Package\Package" => null
    "TYPO3\CMS\Core\Package\PackageInterface" => null
    "TYPO3\CMS\Core\Package\MetaData" => null
    "TYPO3\CMS\Core\Package\MetaData\PackageConstraint" => null
    "TYPO3\CMS\Core\Cache\Backend\SimpleFileBackend" => null
    "TYPO3\CMS\Core\Cache\Frontend\VariableFrontend" => null
    "TYPO3\CMS\Core\DependencyInjection\Cache\ContainerBackend" => null
    "TYPO3\CMS\Core\DependencyInjection\ContainerBuilder" => null
    "TYPO3\CMS\Core\DependencyInjection\ServiceProviderRegistry" => null
.....