Issue #2833116 by smustgrave, mohit_aghera, Ratan Priya, _pratik_, _shY,...

Issue #2833116 by smustgrave, mohit_aghera, Ratan Priya, _pratik_, _shY, alexpott, nitin_lama, acbramley, quietone, larowlan, Peter van den Heuvel, ameymudras, alexpott: When Placing a Block on 'Configure Block' page the originally selected region is lost

(cherry picked from commit 1f94e17f)

core/modules/block_content/src/BlockContentForm.php

@@ -115,6 +115,7 @@ public function save(array $form, FormStateInterface $form_state) {
           [
             'plugin_id' => 'block_content:' . $block->uuid(),
             'theme' => $theme,
+            'region' => $this->getRequest()->query->getString('region'),
           ]
         );
       }

core/modules/block_content/src/Plugin/Menu/LocalAction/BlockContentAddLocalAction.php

@@ -4,13 +4,42 @@
 
 use Drupal\Core\Menu\LocalActionDefault;
 use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Routing\RouteProviderInterface;
 use Drupal\Core\Url;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\RequestStack;
 
 /**
  * Modifies the 'Add content block' local action.
  */
 class BlockContentAddLocalAction extends LocalActionDefault {
 
+  /**
+   * Constructs a BlockContentAddLocalAction object.
+   */
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    $plugin_definition,
+    RouteProviderInterface $routeProvider,
+    protected RequestStack $requestStack,
+  ) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition, $routeProvider);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('router.route_provider'),
+      $container->get('request_stack'),
+    );
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -20,6 +49,12 @@ public function getOptions(RouteMatchInterface $route_match) {
     if ($theme = $route_match->getParameter('theme')) {
       $options['query']['theme'] = $theme;
     }
+
+    // If the current request has a region, append it to the query string.
+    if ($region = $this->requestStack->getCurrentRequest()->query->getString('region')) {
+      $options['query']['region'] = $region;
+    }
+
     // Adds a destination on content block listing.
     if ($route_match->getRouteName() == 'entity.block_content.collection') {
       $options['query']['destination'] = Url::fromRoute('<current>')->toString();

core/modules/block_content/tests/src/Functional/BlockContentListTest.php

@@ -71,6 +71,22 @@ protected function setUp(): void {
     ]);
   }
 
+  /**
+   * Tests the region value when a new block is saved.
+   */
+  public function testBlockRegionPlacement(): void {
+    $this->drupalLogin($this->drupalCreateUser($this->permissions));
+    $this->drupalGet("admin/structure/block/library/stark", ['query' => ['region' => 'content']]);
+
+    $this->clickLink('Add content block');
+    $this->assertSession()->statusCodeEquals(200);
+    $edit = [
+      'info[0][value]' => 'foo',
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->fieldValueEquals('region', 'content');
+  }
+
   /**
    * Tests the content block listing page with different permissions.
    */