Ticket #30678: 30678.patch

src/wp-content/themes/twentyfifteen/functions.php

@@ -181 +181 @@
                 $subsets .= ',vietnamese';
         }
 
-        return add_query_arg( array(
-                'family' => urlencode( implode( '|', $fonts ) ),
-                'subset' => urlencode( $subsets ),
-        ), '//fonts.googleapis.com/css' );
+        $font_url = '';
+
+        if ( $fonts ) {
+                $font_url = add_query_arg( array(
+                        'family' => urlencode( implode( '|', $fonts ) ),
+                        'subset' => urlencode( $subsets ),
+                ), '//fonts.googleapis.com/css' );
+        }
+
+        return $font_url;
 }
 endif;