Issue #3427118 by alexpott, phenaproxima, millnut, Wim Leers: If config...

Issue #3427118 by alexpott, phenaproxima, millnut, Wim Leers: If config rollback fails validation, it's impossible to tell what caused the rollback in the first place

(cherry picked from commit 2cf80c1e475acc55aced19db9a7a8375a75eb912)

core/lib/Drupal/Core/Recipe/RecipeCommand.php

@@ -6,6 +6,7 @@
 
 use Drupal\Core\Config\Checkpoint\Checkpoint;
 use Drupal\Core\Config\ConfigImporter;
+use Drupal\Core\Config\ConfigImporterException;
 use Drupal\Core\Config\StorageComparer;
 use Drupal\Core\DrupalKernel;
 use Drupal\Core\Site\Settings;
@@ -87,7 +88,12 @@ protected function execute(InputInterface $input, OutputInterface $output): int
       return 0;
     }
     catch (\Throwable $e) {
-      $this->rollBackToCheckpoint($backup_checkpoint);
+      try {
+        $this->rollBackToCheckpoint($backup_checkpoint);
+      }
+      catch (ConfigImporterException $importer_exception) {
+        $io->error($importer_exception->getMessage());
+      }
       throw $e;
     }
   }

core/tests/Drupal/FunctionalTests/Core/Recipe/RecipeCommandTest.php

@@ -77,6 +77,20 @@ public function testRecipeCommand(): void {
     $this->assertStringContainsString('[notice] A backup checkpoint was not created because nothing has changed since the "Test log message" checkpoint was created.', $process->getOutput());
   }
 
+  /**
+   * Tests that errors during config rollback won't steamroll validation errors.
+   */
+  public function testExceptionOnRollback(): void {
+    $process = $this->applyRecipe('core/tests/fixtures/recipes/config_rollback_exception', 1);
+
+    // The error from the config importer should be visible.
+    $output = $process->getOutput();
+    $this->assertStringContainsString('There were errors validating the config synchronization.', $output);
+    $this->assertStringContainsString('Provides a filter plugin that is in use', $output);
+    // And the exception that actually *caused* the error should be visible too.
+    $this->assertStringContainsString('There were validation errors in system.image:', $process->getErrorOutput());
+  }
+
   /**
    * Asserts that the current set of checkpoints matches the given labels.
    *

core/tests/fixtures/recipes/config_rollback_exception/recipe.yml

+name: Config rollback exception
+install:
+  - filter
+  - media
+config:
+  import:
+    filter: '*'
+    media: '*'
+  actions:
+    filter.format.plain_text:
+      setFilterConfig:
+        instance_id: media_embed
+        configuration: []
+    system.image:
+      # This will cause a validation error, which will trigger a rollback.
+      # The rollback should fail, since the Media module can't be uninstalled
+      # now that the plain_text format is using one of its filters.
+      simple_config_update:
+        non_existent_key: whatever!