diff --git includes/menu.inc includes/menu.inc
index 642e946..3d8e872 100644
--- includes/menu.inc
+++ includes/menu.inc
@@ -1095,6 +1095,38 @@ function menu_tree_all_data($menu_name, $link = NULL, $max_depth = NULL) {
 }
 
 /**
+ * Set the path for determining the active trail of the specified menu tree.
+ *
+ * @param $menu_name
+ *   The name of the affected menu tree.
+ * @param $path
+ *   The path to use when finding the active trail.
+ */
+function menu_tree_set_path($menu_name, $path) {
+  return menu_tree_get_path($menu_name, $path);
+}
+
+/**
+ * Get the path for determining the active trail of the specified menu tree.
+ *
+ * @param $menu_name
+ *   The menu name of the requested tree.
+ * @param $path
+ *   Internal use only.
+ *
+ * @return
+ *   A string containing the path. If no path has been specified with
+ *   menu_tree_set_path(), NULL is returned.
+ */
+function menu_tree_get_path($menu_name, $path = NULL) {
+  $paths = &drupal_static(__FUNCTION__);
+  if (isset($path)) {
+    $paths[$menu_name] = $path;
+  }
+  return isset($paths[$menu_name]) ? $paths[$menu_name] : NULL;
+}
+
+/**
  * Get the data structure representing a named menu tree, based on the current page.
  *
  * The tree order is maintained by storing each parent in an individual
@@ -1119,8 +1151,10 @@ function menu_tree_all_data($menu_name, $link = NULL, $max_depth = NULL) {
 function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail = FALSE) {
   $tree = &drupal_static(__FUNCTION__, array());
 
+  // Check if the active trail has been overridden for this menu tree.
+  $active_path = menu_tree_get_path($menu_name);
   // Load the menu item corresponding to the current page.
-  if ($item = menu_get_item()) {
+  if ($item = menu_get_item($active_path)) {
     if (isset($max_depth)) {
       $max_depth = min($max_depth, MENU_MAX_DEPTH);
     }
@@ -1159,8 +1193,9 @@ function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail =
         // If the item for the current page is accessible, build the tree
         // parameters accordingly.
         if ($item['access']) {
-          // Find a menu link corresponding to the current path.
-          if ($active_link = menu_link_get_preferred()) {
+          // Find a menu link corresponding to the current path. If $active_path
+          // is NULL, let menu_link_get_preferred() determine the path.
+          if ($active_link = menu_link_get_preferred($active_path)) {
             // The active link may only be taken into account to build the
             // active trail, if it resides in the requested menu. Otherwise,
             // we'd needlessly re-run _menu_build_tree() queries for every menu
diff --git modules/simpletest/tests/menu.test modules/simpletest/tests/menu.test
index 0c002e2..f2e1148 100644
--- modules/simpletest/tests/menu.test
+++ modules/simpletest/tests/menu.test
@@ -560,6 +560,42 @@ class MenuTreeDataTestCase extends DrupalUnitTestCase {
 }
 
 /**
+ * Menu tree display related tests.
+ */
+class MenuTreeTestCase extends DrupalWebTestCase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Menu tree display',
+      'description' => 'Tests menu tree display functions.',
+      'group' => 'Menu',
+    );
+  }
+
+  /**
+   * Test that menu_tree_set_path() affects menu tree generation.
+   */
+  function testMenuTreeSetPath() {
+    $path = 'admin/config/system/site-information';
+    $menu_name = 'management';
+
+    // Verify the test path is not originally in the menu tree.
+    $tree = drupal_render(menu_tree($menu_name));
+    $this->assert(strpos($tree, $path) === FALSE, t('Test link does not exist in menu tree.'));
+
+    // Set the active path of the menu tree to the test path.
+    drupal_flush_all_caches();
+    menu_tree_set_path($menu_name, $path);
+
+    // Check if the test path is returned by menu_tree_get_path().
+    $this->assertIdentical($path, menu_tree_get_path($menu_name), t('Test link set by menu_tree_set_path().'));
+
+    // Check if the test path is in the menu tree.
+    $tree = drupal_render(menu_tree($menu_name));
+    $this->assert(strpos($tree, $path) !== FALSE, t('Test link exists in menu tree.'));
+  }
+}
+
+/**
  * Menu breadcrumbs related tests.
  */
 class MenuBreadcrumbTestCase extends DrupalWebTestCase {