Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.855
diff -u -p -r1.855 common.inc
--- includes/common.inc	22 Jan 2009 05:01:39 -0000	1.855
+++ includes/common.inc	23 Jan 2009 10:12:14 -0000
@@ -3199,7 +3199,10 @@ function drupal_alter($type, &$data) {
  *
  * Recursively iterates over each of the array elements, generating HTML code.
  * This function is usually called from within a another function, like
- * drupal_get_form() or node_view().
+ * drupal_get_form() or node_view(). Elements are sorted internally using
+ * uasort(). Since this is expensive, when passing already sorted elements to
+ * drupal_render(), for example from a database query, set
+ * $elements['#sorted'] = TRUE to avoid sorting them a second time.
  *
  * @param $elements
  *   The structured array describing the data to be rendered.
@@ -3207,6 +3210,7 @@ function drupal_alter($type, &$data) {
  *   The rendered HTML.
  */
 function drupal_render(&$elements) {
+  // Early-return nothing if user does not have access.
   if (!isset($elements) || (isset($elements['#access']) && !$elements['#access'])) {
     return NULL;
   }
@@ -3230,15 +3234,19 @@ function drupal_render(&$elements) {
     }
   }
 
-  $content = '';
-  // Either the elements did not go through form_builder or one of the children
-  // has a #weight.
-  if (!isset($elements['#sorted'])) {
-    uasort($elements, "element_sort");
+  // Sort the elements by weight, if there are any children, and they have not
+  // been sorted elsewhere already, for example by a database query. Pre-sorted
+  // elements should have $elements['#sorted'] set to TRUE to avoid unnecessary
+  // calls to uasort().
+  $children = !isset($elements['#children']) ? element_children($elements) : FALSE;
+  if (empty($elements['#sorted']) && $children) {
+    uasort($elements, 'element_sort');
+    $elements['#sorted'] = TRUE;
   }
+
+  $content = '';
   $elements += array('#title' => NULL, '#description' => NULL);
   if (!isset($elements['#children'])) {
-    $children = element_children($elements);
     // Render all the children that use a theme function.
     if (isset($elements['#theme']) && empty($elements['#theme_used'])) {
       $elements['#theme_used'] = TRUE;
Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.685
diff -u -p -r1.685 comment.module
--- modules/comment/comment.module	22 Jan 2009 12:46:06 -0000	1.685
+++ modules/comment/comment.module	23 Jan 2009 10:12:16 -0000
@@ -498,6 +498,7 @@ function comment_nodeapi_view($node, $te
     if ($node->comment && (bool)menu_get_object() && $node->build_mode != NODE_BUILD_PREVIEW) {
       $node->content['comments'] = array(
         '#markup' => comment_render($node),
+        '#sorted' => TRUE,
       );
     }
   }
Index: modules/taxonomy/taxonomy.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/taxonomy/taxonomy.module,v
retrieving revision 1.454
diff -u -p -r1.454 taxonomy.module
--- modules/taxonomy/taxonomy.module	14 Jan 2009 21:16:20 -0000	1.454
+++ modules/taxonomy/taxonomy.module	23 Jan 2009 10:12:17 -0000
@@ -76,7 +76,8 @@ function taxonomy_nodeapi_view($node) {
   
   $node->content['links']['terms'] = array(
     '#type' => 'node_links',
-    '#value' => $links
+    '#value' => $links,
+    '#sorted' => TRUE,
   );
 }