Issue #3218103 by phenaproxima, rpayanm, joachim: media module creates fields with the field prefix hardcoded and ignores the configuration

core/modules/media/src/MediaSourceBase.php

@@ -301,9 +301,14 @@ abstract class MediaSourceBase extends PluginBase implements MediaSourceInterfac
    *   returned. Otherwise, a new, unused one is generated.
    */
   protected function getSourceFieldName() {
+    // If the Field UI module is installed, and has a specific prefix
+    // configured, use that. Otherwise, just default to using 'field_' as
+    // a prefix, which is the default that Field UI ships with.
+    $prefix = $this->configFactory->get('field_ui.settings')
+      ->get('field_prefix') ?? 'field_';
     // Some media sources are using a deriver, so their plugin IDs may contain
     // a separator (usually ':') which is not allowed in field names.
-    $base_id = 'field_media_' . str_replace(static::DERIVATIVE_SEPARATOR, '_', $this->getPluginId());
+    $base_id = $prefix . 'media_' . str_replace(static::DERIVATIVE_SEPARATOR, '_', $this->getPluginId());
     $tries = 0;
     $storage = $this->entityTypeManager->getStorage('field_storage_config');
 

core/modules/media/tests/src/Kernel/MediaSourceTest.php

@@ -15,6 +15,11 @@ use Drupal\media\Entity\MediaType;
  */
 class MediaSourceTest extends MediaKernelTestBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field_ui'];
+
   /**
    * Tests that metadata is correctly mapped irrespective of how media is saved.
    */
@@ -506,6 +511,24 @@ class MediaSourceTest extends MediaKernelTestBase {
     $this->assertTrue($field->isRequired(), 'Field is not required.');
     $this->assertEquals('Test source with constraints', $field->label(), 'Incorrect label is used.');
     $this->assertSame('test_constraints_type', $field->getTargetBundle(), 'Field is not targeting correct bundle.');
+
+    // Test that new source fields respect the configured field prefix, no
+    // prefix at all if that's what's configured.
+    $this->installConfig('field_ui');
+    $this->config('field_ui.settings')
+      ->set('field_prefix', 'prefix_')
+      ->save();
+    $type = MediaType::create([
+      'id' => $this->randomMachineName(),
+      'label' => $this->randomString(),
+      'source' => 'test',
+    ]);
+    $this->assertSame('prefix_media_test', $type->getSource()->createSourceField($type)->getName());
+
+    $this->config('field_ui.settings')
+      ->set('field_prefix', '')
+      ->save();
+    $this->assertSame('media_test', $type->getSource()->createSourceField($type)->getName());
   }
 
   /**