Issue #3252100 by amateescu, catch, Tim Bozeman: Set revision_default when publishing

core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php

@@ -708,10 +708,12 @@ protected function doSave($id, EntityInterface $entity) {
 
     $this->populateAffectedRevisionTranslations($entity);
 
-    // Populate the "revision_default" flag. We skip this when we are resaving
-    // the revision because this is only allowed for default revisions, and
-    // these cannot be made non-default.
-    if ($this->entityType->isRevisionable() && $entity->isNewRevision()) {
+    // Populate the "revision_default" flag. Skip this when we are resaving
+    // the revision, and the flag is set to FALSE, since it is not possible to
+    // set a previously default revision to non-default. However, setting a
+    // previously non-default revision to default is allowed for advanced
+    // use-cases.
+    if ($this->entityType->isRevisionable() && ($entity->isNewRevision() || $entity->isDefaultRevision())) {
       $revision_default_key = $this->entityType->getRevisionMetadataKey('revision_default');
       $entity->set($revision_default_key, $entity->isDefaultRevision());
     }

core/modules/workspaces/tests/src/Kernel/WorkspaceIntegrationTest.php

@@ -356,6 +356,13 @@ public function testWorkspaces() {
     $this->assertWorkspaceStatus($test_scenarios['push_stage_to_live'], 'node');
     $this->assertWorkspaceAssociation($expected_workspace_association['push_stage_to_live'], 'node');
 
+    // Check that all the revisions that were published to 'Live' were also
+    // marked as default revisions in their revision metadata field.
+    $published_revisions = $this->entityTypeManager->getStorage('node')->loadMultipleRevisions(array_keys($expected['node']));
+    foreach ($published_revisions as $published_revision) {
+      $this->assertTrue($published_revision->wasDefaultRevision());
+    }
+
     // Check that there are no more revisions to push.
     $this->assertEmpty($workspace_publisher->getDifferringRevisionIdsOnSource());
   }

core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionsTest.php

@@ -261,4 +261,32 @@ public function testIsLatestAffectedRevisionTranslation() {
     $this->assertTrue($en_revision->isLatestTranslationAffectedRevision());
   }
 
+  /**
+   * Tests the automatic handling of the "revision_default" flag.
+   *
+   * @covers \Drupal\Core\Entity\ContentEntityStorageBase::doSave
+   */
+  public function testDefaultRevisionFlag() {
+    // Create a basic EntityTestMulRev entity and save it.
+    $entity = EntityTestMulRev::create();
+    $entity->save();
+    $this->assertTrue($entity->wasDefaultRevision());
+
+    // Create a new default revision.
+    $entity->setNewRevision(TRUE);
+    $entity->save();
+    $this->assertTrue($entity->wasDefaultRevision());
+
+    // Create a new non-default revision.
+    $entity->setNewRevision(TRUE);
+    $entity->isDefaultRevision(FALSE);
+    $entity->save();
+    $this->assertFalse($entity->wasDefaultRevision());
+
+    // Turn the previous non-default revision into a default revision.
+    $entity->isDefaultRevision(TRUE);
+    $entity->save();
+    $this->assertTrue($entity->wasDefaultRevision());
+  }
+
 }