Issue #2092245 by jbrown, rpayanm: SVGZ isn't served with correct encoding

.htaccess

@@ -24,6 +24,10 @@ ErrorDocument 404 /index.php
 # Set the default handler.
 DirectoryIndex index.php index.html index.htm
 
+# Add correct encoding for SVGZ.
+AddType image/svg+xml svg svgz
+AddEncoding gzip svgz
+
 # Override PHP settings that cannot be changed at runtime. See
 # sites/default/default.settings.php and
 # Drupal\Core\DrupalKernel::bootEnvironment() for settings that can be

core/modules/system/src/Tests/System/HtaccessTest.php

@@ -10,7 +10,7 @@
 use Drupal\simpletest\WebTestBase;
 
 /**
- * Tests access restrictions provided by the default .htaccess file.
+ * Tests .htaccess is working correctly.
  *
  * @group system
  */
@@ -68,4 +68,14 @@ protected function assertNoFileAccess($path) {
     $this->assertResponse(403);
   }
 
+  /**
+   * Tests that SVGZ files are served with Content-Encoding: gzip.
+   */
+  public function testSvgzContentEncoding() {
+    $this->drupalGet('core/modules/system/tests/logo.svgz');
+    $this->assertResponse(200);
+    $header = $this->drupalGetHeader('Content-Encoding');
+    $this->assertEqual($header, 'gzip');
+  }
+
 }