Issue #3254553 by Leon Kessler, Berdir, Bladedu, cmlara:...

Issue #3254553 by Leon Kessler, Berdir, Bladedu, cmlara: FileUrlGenerator::generate() does not work with externally hosted files using stream wrappers

core/lib/Drupal/Core/File/FileUrlGenerator.php

@@ -186,8 +186,18 @@ public function generate(string $uri): Url {
       return Url::fromUri(urldecode($options['path']), $options);
     }
     elseif ($wrapper = $this->streamWrapperManager->getViaUri($uri)) {
-      // Attempt to return an external URL using the appropriate wrapper.
-      return Url::fromUri('base:' . $this->transformRelative(urldecode($wrapper->getExternalUrl()), FALSE));
+      $external_url = $wrapper->getExternalUrl();
+      $options = UrlHelper::parse($external_url);
+
+      // @todo Switch to dependency injected request_context service after
+      // https://www.drupal.org/project/drupal/issues/3256884 is fixed.
+      if (UrlHelper::externalIsLocal($external_url, \Drupal::service('router.request_context')->getCompleteBaseUrl())) {
+        // Attempt to return an external URL using the appropriate wrapper.
+        return Url::fromUri('base:' . $this->transformRelative(urldecode($options['path']), FALSE), $options);
+      }
+      else {
+        return Url::fromUri(urldecode($options['path']), $options);
+      }
     }
     throw new InvalidStreamWrapperException();
   }

core/modules/file/tests/file_test/file_test.services.yml

@@ -11,3 +11,7 @@ services:
     class: Drupal\file_test\StreamWrapper\DummyStreamWrapper
     tags:
       - { name: stream_wrapper, scheme: dummy }
+  stream_wrapper.dummy_external_readonly:
+    class: Drupal\file_test\StreamWrapper\DummyExternalReadOnlyWrapper
+    tags:
+      - { name: stream_wrapper, scheme: dummy-external-readonly }

core/modules/file/tests/file_test/src/StreamWrapper/DummyExternalReadOnlyWrapper.php

+<?php
+
+namespace Drupal\file_test\StreamWrapper;
+
+use Drupal\Core\StreamWrapper\ReadOnlyStream;
+use Drupal\Core\StreamWrapper\StreamWrapperInterface;
+
+/**
+ * Helper class for testing the stream wrapper registry.
+ *
+ * Dummy external stream wrapper implementation (dummy-external-readonly://).
+ */
+class DummyExternalReadOnlyWrapper extends ReadOnlyStream {
+
+  /**
+   * @inheritDoc
+   */
+  public static function getType() {
+    return StreamWrapperInterface::READ_VISIBLE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function getName() {
+    return t('Dummy external stream wrapper (readonly)');
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function getDescription() {
+    return t('Dummy external read-only stream wrapper for testing.');
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function getExternalUrl() {
+    [, $target] = explode('://', $this->uri, 2);
+    return 'https://www.dummy-external-readonly.com/' . $target;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function realpath() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function dirname($uri = NULL) {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function dir_closedir() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function dir_opendir($path, $options) {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function dir_readdir() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function dir_rewinddir() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_cast($cast_as) {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_close() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_eof() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_read($count) {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_seek($offset, $whence = SEEK_SET) {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_set_option($option, $arg1, $arg2) {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_stat() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function stream_tell() {
+    return FALSE;
+  }
+
+  /**
+   * @inheritDoc
+   */
+  public function url_stat($path, $flags) {
+    return FALSE;
+  }
+
+}

core/tests/Drupal/KernelTests/Core/File/FileUrlGeneratorTest.php

@@ -188,7 +188,7 @@ public function testGenerateURI($filepath, $expected) {
 
     // No schema file.
     $url = $this->fileUrlGenerator->generate($filepath);
-    $this->assertEquals($expected, $url->getUri());
+    $this->assertEquals($expected, $url->toUriString());
   }
 
   /**
@@ -251,6 +251,26 @@ public function providerGenerateURI() {
           'https://www.example.com/core/assets/vendor/jquery/jquery.min.js',
           'https://www.example.com/core/assets/vendor/jquery/jquery.min.js',
         ],
+      'external stream wrapper' =>
+        [
+          'dummy-external-readonly://core/assets/vendor/jquery/jquery.min.js',
+          'https://www.dummy-external-readonly.com/core/assets/vendor/jquery/jquery.min.js',
+        ],
+      'external stream wrapper with query string' =>
+        [
+          'dummy-external-readonly://core/assets/vendor/jquery/jquery.min.js?foo=bar',
+          'https://www.dummy-external-readonly.com/core/assets/vendor/jquery/jquery.min.js?foo=bar',
+        ],
+      'external stream wrapper with hashes' =>
+        [
+          'dummy-external-readonly://core/assets/vendor/jquery/jquery.min.js#whizz',
+          'https://www.dummy-external-readonly.com/core/assets/vendor/jquery/jquery.min.js#whizz',
+        ],
+      'external stream wrapper with query string and hashes' =>
+        [
+          'dummy-external-readonly://core/assets/vendor/jquery/jquery.min.js?foo=bar#whizz',
+          'https://www.dummy-external-readonly.com/core/assets/vendor/jquery/jquery.min.js?foo=bar#whizz',
+        ],
     ];
   }