Ticket #16282: both.16282.2.diff

Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php    (revision 17357)
+++ wp-includes/taxonomy.php    (working copy)
@@ -879,7 +879,7 @@
 
        if ( 'slug' == $field ) {
                $field = 't.slug';
-               $value = sanitize_title($value);
+               $value = sanitize_title_for_query($value);
                if ( empty($value) )
                        return false;
        } else if ( 'name' == $field ) {
@@ -2824,7 +2824,12 @@
                if ( is_int($term) ) {
                        $term = &get_term($term, $taxonomy);
                } else {
-                       $term = &get_term_by('slug', $term, $taxonomy);
+                       $term_obj = &get_term_by('slug', $term, $taxonomy);
+
+                       if ( !$term_obj || is_wp_error($term_obj) )
+                               $term_obj = &get_term_by('name', $term, $taxonomy);
+
+                       $term = &$term_obj;
                }
        }