Inject the database into the installer script when possible (#40724)

* Inject the database into the installer script when possible

* Proxy the database in the legacy installer class

Author: laoneo

libraries/src/Installer/InstallerAdapter.php

@@ -21,6 +21,7 @@
 use Joomla\Database\DatabaseAwareInterface;
 use Joomla\Database\DatabaseAwareTrait;
 use Joomla\Database\DatabaseDriver;
+use Joomla\Database\DatabaseInterface;
 use Joomla\DI\Container;
 use Joomla\DI\ContainerAwareInterface;
 use Joomla\DI\ContainerAwareTrait;
@@ -996,6 +997,11 @@ function (Container $container) use ($classname) {
         // Create a new instance
         $this->parent->manifestClass = $container->get(InstallerScriptInterface::class);
 
+        // Set the database
+        if ($this->parent->manifestClass instanceof DatabaseAwareInterface) {
+            $this->parent->manifestClass->setDatabase($container->get(DatabaseInterface::class));
+        }
+
         // And set this so we can copy it later
         $this->manifest_script = $manifestScript;
     }

libraries/src/Installer/LegacyInstallerScript.php

@@ -9,6 +9,11 @@
 
 namespace Joomla\CMS\Installer;
 
+use Joomla\CMS\Factory;
+use Joomla\Database\DatabaseAwareInterface;
+use Joomla\Database\DatabaseAwareTrait;
+use Joomla\Database\Exception\DatabaseNotFoundException;
+
 // phpcs:disable PSR1.Files.SideEffects
 \defined('_JEXEC') or die;
 // phpcs:enable PSR1.Files.SideEffects
@@ -18,8 +23,10 @@
  *
  * @since  4.2.0
  */
-class LegacyInstallerScript implements InstallerScriptInterface
+class LegacyInstallerScript implements InstallerScriptInterface, DatabaseAwareInterface
 {
+    use DatabaseAwareTrait;
+
     /**
      * @var    \stdClass
      * @since  4.2.0
@@ -168,6 +175,15 @@ private function callOnScript(string $name, array $arguments): bool
             return true;
         }
 
+        if ($this->installerScript instanceof DatabaseAwareInterface) {
+            try {
+                $this->installerScript->setDatabase($this->getDatabase());
+            } catch (DatabaseNotFoundException $e) {
+                @trigger_error(sprintf('Database must be set, this will not be caught anymore in 6.0 in %s.', __METHOD__), E_USER_DEPRECATED);
+                $this->installerScript->setDatabase(Factory::getContainer()->get(DatabaseInterface::class));
+            }
+        }
+
         $return = $this->__call($name, $arguments);
 
         // When function doesn't have a return value, assume it succeeded