Issue #2585899 by willzyx, mr.baileys, esod, dawehner:...

Issue #2585899 by willzyx, mr.baileys, esod, dawehner: HtmlResponseAttachmentsProcessor::processHtmlHeadLink produces invalid HTTP Link header

core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php

@@ -419,9 +419,13 @@ protected function processHtmlHeadLink(array $html_head_link) {
 
       if ($should_add_header) {
         // Also add a HTTP header "Link:".
-        $href = '<' . Html::escape($attributes['href'] . '>');
+        $href = '<' . Html::escape($attributes['href']) . '>';
         unset($attributes['href']);
-        $attached['http_header'][] = ['Link', $href . drupal_http_header_attributes($attributes), TRUE];
+        if ($param = drupal_http_header_attributes($attributes)) {
+          $href .= ';' . $param;
+        }
+
+        $attached['http_header'][] = ['Link', $href, FALSE];
       }
     }
     return $attached;

core/modules/node/src/Tests/NodeViewTest.php

@@ -2,6 +2,8 @@
 
 namespace Drupal\node\Tests;
 
+use Drupal\Component\Utility\Html;
+
 /**
  * Tests the node/{node} page.
  *
@@ -63,6 +65,24 @@ public function testHtmlHeadLinks() {
     $this->assertEqual($result[0]['href'], $node->url('edit-form'));
   }
 
+  /**
+   * Tests the Link header.
+   */
+  public function testLinkHeader() {
+    $node = $this->drupalCreateNode();
+
+    $expected = [
+      '<' . Html::escape($node->url('canonical')) . '>; rel="canonical"',
+      '<' . Html::escape($node->url('canonical'), ['alias' => TRUE]) . '>; rel="shortlink"',
+      '<' . Html::escape($node->url('revision')) . '>; rel="revision"',
+    ];
+
+    $this->drupalGet($node->urlInfo());
+
+    $links = explode(',', $this->drupalGetHeader('Link'));
+    $this->assertEqual($links, $expected);
+  }
+
   /**
    * Tests that we store and retrieve multi-byte UTF-8 characters correctly.
    */

core/modules/system/src/Tests/Render/HtmlResponseAttachmentsTest.php

@@ -54,6 +54,14 @@ public function testAttachments() {
     // Repeat for the cache.
     $this->drupalGet('/render_attached_test/head');
     $this->assertHeader('X-Drupal-Cache', 'HIT');
+
+    // Test ['#attached']['html_head_link'] when outputted as HTTP header.
+    $this->drupalGet('/render_attached_test/html_header_link');
+    $expected_link_headers = [
+      '</foo?bar=&lt;baz&gt;&amp;baz=false>; rel="alternate"',
+      '</foo/bar>; hreflang="nl"; rel="alternate"',
+    ];
+    $this->assertEqual($this->drupalGetHeader('link'), implode(',', $expected_link_headers));
   }
 
   /**

core/modules/system/tests/modules/render_attached_test/render_attached_test.routing.yml

@@ -19,6 +19,13 @@ render_attached.head:
   requirements:
     _access: 'TRUE'
 
+render_attached.html_header_link:
+  path: '/render_attached_test/html_header_link'
+  defaults:
+    _controller: '\Drupal\render_attached_test\Controller\RenderAttachedTestController::htmlHeaderLink'
+  requirements:
+    _access: 'TRUE'
+
 render_attached.feed_single:
   path: '/render_attached_test/feed'
   defaults:

core/modules/system/tests/modules/render_attached_test/src/Controller/RenderAttachedTestController.php

@@ -69,4 +69,18 @@ public function feed() {
     return $render;
   }
 
+  /**
+   * Test HTTP header rendering for link.
+   *
+   * @return array
+   *   A render array using the 'html_head_link' directive.
+   */
+  public function htmlHeaderLink() {
+    $render = [];
+    $render['#attached']['html_head_link'][] = [['href' => '/foo?bar=<baz>&baz=false', 'rel' => 'alternate'], TRUE];
+    $render['#attached']['html_head_link'][] = [['href' => '/not-added-to-http-headers', 'rel' => 'alternate'], FALSE];
+    $render['#attached']['html_head_link'][] = [['href' => '/foo/bar', 'hreflang' => 'nl', 'rel' => 'alternate'], TRUE];
+    return $render;
+  }
+
 }