diff --git a/.htaccess b/.htaccess
index 7ccb6a2..4e49691 100644
--- a/.htaccess
+++ b/.htaccess
@@ -19,6 +19,10 @@ 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_environment_initialize() in
 # includes/bootstrap.inc for settings that can be changed at runtime.
diff --git a/modules/simpletest/drupal_web_test_case.php b/modules/simpletest/drupal_web_test_case.php
index 271efff..fb5c6a6 100644
--- a/modules/simpletest/drupal_web_test_case.php
+++ b/modules/simpletest/drupal_web_test_case.php
@@ -2257,8 +2257,13 @@ class DrupalWebTestCase extends DrupalTestCase {
             if ($wrapperNode) {
               // ajax.js adds an enclosing DIV to work around a Safari bug.
               $newDom = new DOMDocument();
+              // DOM can load HTML soup. But, HTML soup can throw warnings,
+              // suppress them.
               $newDom->loadHTML('<div>' . $command['data'] . '</div>');
-              $newNode = $dom->importNode($newDom->documentElement->firstChild->firstChild, TRUE);
+              // Suppress warnings thrown when duplicate HTML IDs are
+              // encountered. This probably means we are replacing an element
+              // with the same ID.
+              $newNode = @$dom->importNode($newDom->documentElement->firstChild->firstChild, TRUE);
               $method = isset($command['method']) ? $command['method'] : $ajax_settings['method'];
               // The "method" is a jQuery DOM manipulation function. Emulate
               // each one using PHP's DOMNode API.