Index: misc/autocomplete.js
===================================================================
RCS file: /cvs/drupal/drupal/misc/autocomplete.js,v
retrieving revision 1.36
diff -u -r1.36 autocomplete.js
--- misc/autocomplete.js	30 Apr 2010 05:23:43 -0000	1.36
+++ misc/autocomplete.js	9 Jun 2010 00:43:33 -0000
@@ -106,6 +106,7 @@
  */
 Drupal.jsAC.prototype.select = function (node) {
   this.input.value = $(node).data('autocompleteValue');
+  $(this.input).trigger('autocomplete_select', [node]);
 };
 
 /**
@@ -157,7 +158,7 @@
 Drupal.jsAC.prototype.hidePopup = function (keycode) {
   // Select item if the right key or mousebutton was pressed.
   if (this.selected && ((keycode && keycode != 46 && keycode != 8 && keycode != 27) || !keycode)) {
-    this.input.value = $(this.selected).data('autocompleteValue');
+    this.select(this.selected);
   }
   // Hide popup.
   var popup = this.popup;