[BUGFIX] Make sure AdditionalConfiguration is loaded

This loads AdditionalConfiguration.php even if LocalConfiguration.php
could not be loaded.

Before this change, configuration for the install tool could only be
given if a LocalConfiguration was present.

With this change, AdditionalConfiguration (if present) is applied
on top of DefaultConfiguration.

In a FIRST_INSTALL scenario, this enables (among others) the correct
evaluation of a set trustedHostsPattern in AdditionalConfiguration.

Resolves: #88846
Resolves: #86356
Releases: master, 9.5
Change-Id: I6c0e39eb57ce6b28b493f1ae9716b478b643dda9
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61374


Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Marc von Schalscha <msa@starfinanz.de>
Reviewed-by: Maik Peuser <maik.peuser@verdure.de>
Reviewed-by: Tobi Kretschmann <tobi@tobishome.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Randy Fay <randy@randyfay.com>
Tested-by: Maik Peuser <maik.peuser@verdure.de>
Tested-by: Tobi Kretschmann <tobi@tobishome.de>

typo3/sysext/core/Classes/Configuration/ConfigurationManager.php

@@ -340,13 +340,15 @@ class ConfigurationManager
             } else {
                 throw new \UnexpectedValueException('LocalConfiguration invalid.', 1349272276);
             }
-            if (@is_file($this->getAdditionalConfigurationFileLocation())) {
-                require $this->getAdditionalConfigurationFileLocation();
-            }
         } else {
-            // No LocalConfiguration (yet), load DefaultConfiguration only
+            // No LocalConfiguration (yet), load DefaultConfiguration
             $GLOBALS['TYPO3_CONF_VARS'] = $this->getDefaultConfiguration();
         }
+
+        // Load AdditionalConfiguration
+        if (@is_file($this->getAdditionalConfigurationFileLocation())) {
+            require $this->getAdditionalConfigurationFileLocation();
+        }
     }
 
     /**