Issue #2335345 by tstoeckler: Fixed Entity\Migration::getProcessPlugins() can...

Issue #2335345 by tstoeckler: Fixed Entity\Migration::getProcessPlugins() can return NULL but should always return an array.

core/modules/migrate/src/Entity/Migration.php

@@ -214,6 +214,7 @@ public function getProcessPlugins(array $process = NULL) {
     }
     $index = serialize($process);
     if (!isset($this->processPlugins[$index])) {
+      $this->processPlugins[$index] = array();
       foreach ($this->getProcessNormalized($process) as $property => $configurations) {
         $this->processPlugins[$index][$property] = array();
         foreach ($configurations as $configuration) {

core/modules/migrate/tests/src/Unit/Entity/MigrationTest.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\migrate\Unit\Entity\MigrationTest.
+ */
+
+namespace Drupal\Tests\migrate\Unit\Entity;
+
+use Drupal\migrate\Entity\Migration;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * Tests the migrate entity.
+ *
+ * @coversDefaultClass \Drupal\migrate\Entity\Migration
+ */
+class MigrationTest extends UnitTestCase {
+
+  /**
+   * Tests Migration::getProcessPlugins()
+   *
+   * @covers ::getProcessPlugins()
+   */
+  public function testGetProcessPlugins() {
+    $migration = new Migration([], 'migration');
+    $this->assertEquals([], $migration->getProcessPlugins([]));
+  }
+
+}