Issue #3317745 by heykarthikwithu, mkalkbrenner, catch, smustgrave, Schoenef: CSS Aggregation should not rewrite # url

core/lib/Drupal/Core/Asset/CssOptimizer.php

@@ -90,8 +90,8 @@ class CssOptimizer implements AssetOptimizerInterface {
     // Store base path.
     $this->rewriteFileURIBasePath = $css_base_path . '/';
 
-    // Anchor all paths in the CSS with its base URL, ignoring external and absolute paths.
+    // Anchor all paths in the CSS with its base URL, ignoring external and absolute paths and paths starting with '#'.
-    return preg_replace_callback('/url\(\s*[\'"]?(?![a-z]+:|\/+)([^\'")]+)[\'"]?\s*\)/i', [$this, 'rewriteFileURI'], $contents);
+    return preg_replace_callback('/url\(\s*[\'"]?(?![a-z]+:|\/+|#|%23)([^\'")]+)[\'"]?\s*\)/i', [$this, 'rewriteFileURI'], $contents);
   }
 
   /**

core/tests/Drupal/Tests/Core/Asset/CssOptimizerUnitTest.php

@@ -222,6 +222,18 @@ class CssOptimizerUnitTest extends UnitTestCase {
         ],
         file_get_contents($absolute_path . 'quotes.css.optimized.css'),
       ],
+      [
+        [
+          'group' => -100,
+          'type' => 'file',
+          'weight' => 0.013,
+          'media' => 'all',
+          'preprocess' => TRUE,
+          'data' => $path . 'import3.css',
+          'basename' => 'import3.css',
+        ],
+        file_get_contents($absolute_path . 'import3.css.optimized.css'),
+      ],
     ];
   }
 

core/tests/Drupal/Tests/Core/Asset/css_test_files/import3.css

@@ -0,0 +1,6 @@
+div {
+  clip-path: url('#clip-cloud');
+}
+div {
+  clip-path: url('/abc/#clip-cloud');
+}

core/tests/Drupal/Tests/Core/Asset/css_test_files/import3.css.optimized.css

@@ -0,0 +1 @@
+div{clip-path:url('#clip-cloud');}div{clip-path:url('/abc/#clip-cloud');}