Ticket #11981: post-template-icon_dir-fix.diff

wp-includes/post-template.php

@@ -1009 +1009 @@
         } elseif ( $src = wp_mime_type_icon( $post->ID ) ) {
                 // No thumb, no image. We'll look for a mime-related icon instead.
 
-                $icon_dir = apply_filters( 'icon_dir', get_template_directory() . '/images' );
+                $icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/crystal' );
                 $src_file = $icon_dir . '/' . basename($src);
         }