Index: includes/batch.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/batch.inc,v
retrieving revision 1.39
diff -u -p -r1.39 batch.inc
--- includes/batch.inc	21 Sep 2009 07:56:07 -0000	1.39
+++ includes/batch.inc	21 Sep 2009 20:20:02 -0000
@@ -1,7 +1,6 @@
 <?php
 // $Id: batch.inc,v 1.39 2009/09/21 07:56:07 dries Exp $
 
-
 /**
  * @file
  * Batch processing API for processes to run in multiple HTTP requests.
@@ -445,7 +444,15 @@ function _batch_finished() {
     // If no redirection happened, save the final $form_state value to be
     // retrieved by drupal_get_form() and redirect to the originating page.
     $_SESSION['batch_form_state'] = $_batch['form_state'];
-    drupal_goto($_batch['source_page']);
+    if (empty($_batch['redirect_callback'])) {
+      $redirect_callback = 'drupal_goto';
+    }
+    else {
+      $redirect_callback = $_batch['redirect_callback'];
+    }
+    if (function_exists($redirect_callback)) {
+      $redirect_callback($_batch['source_page'], array('op' => 'finish', 'id' => $batch['id']));
+    }
   }
 }
 
Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.375
diff -u -p -r1.375 form.inc
--- includes/form.inc	21 Sep 2009 06:44:13 -0000	1.375
+++ includes/form.inc	21 Sep 2009 20:14:39 -0000
@@ -2921,7 +2921,7 @@ function batch_set($batch_definition) {
  * Process the batch.
  *
  * Unless the batch has been marked with 'progressive' = FALSE, the function
- * issues a drupal_goto and thus ends page execution.
+ * issues a drupal_goto() and thus ends page execution.
  *
  * This function is generally not needed in form submit handlers;
  * Form API takes care of batches that were set during form submission.
@@ -2931,8 +2931,13 @@ function batch_set($batch_definition) {
  * @param $url
  *   (optional - should only be used for separate scripts like update.php)
  *   URL of the batch processing page.
+ * @param $redirect_callback
+ *   (optional) A function to call to redirect to the progressive processing
+ *   page. By default, drupal_goto() is used to redirect to a page which will do
+ *   the progressive page. Specifying another function will allow the
+ *   progressive processing to be processed differently.
  */
-function batch_process($redirect = NULL, $url = NULL) {
+function batch_process($redirect = NULL, $url = NULL, $redirect_callback = NULL) {
   $batch =& batch_get();
 
   drupal_theme_initialize();
@@ -2947,6 +2952,7 @@ function batch_process($redirect = NULL,
       'source_page' => $_GET['q'],
       'redirect' => $redirect,
       'theme' => $GLOBALS['theme_key'],
+      'redirect_callback' => $redirect_callback,
     );
     $batch += $process_info;
 
@@ -2984,7 +2990,12 @@ function batch_process($redirect = NULL,
       // Set the batch number in the session to guarantee that it will stay alive.
       $_SESSION['batches'][$batch['id']] = TRUE;
 
-      drupal_goto($batch['url'], 'op=start&id=' . $batch['id']);
+      if (empty($redirect_callback)) {
+        $redirect_callback = 'drupal_goto';
+      }
+      if (function_exists($redirect_callback)) {
+        $redirect_callback($batch['url'], array('op' => 'start', 'id' => $batch['id']));
+      }
     }
     else {
       // Non-progressive execution: bypass the whole progressbar workflow
Index: includes/update.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/update.inc,v
retrieving revision 1.10
diff -u -p -r1.10 update.inc
--- includes/update.inc	21 Sep 2009 08:07:07 -0000	1.10
+++ includes/update.inc	21 Sep 2009 20:13:34 -0000
@@ -364,8 +364,11 @@ class DrupalUpdateException extends Exce
  *   scripts like update.php).
  * @param $batch
  *   Optional parameters to pass into the batch API.
+ * @param $redirect_callback
+ *   (optional) A function to call to redirect to the progressive processing
+ *   page.
  */
-function update_batch($start, $redirect = NULL, $url = NULL, $batch = array()) {
+function update_batch($start, $redirect = NULL, $url = NULL, $batch = array(), $redirect_callback = NULL) {
   // During the update, bring the site offline so that schema changes do not
   // affect visiting users.
   $_SESSION['maintenance_mode'] = variable_get('maintenance_mode', FALSE);
@@ -396,7 +399,7 @@ function update_batch($start, $redirect 
     'file' => 'includes/update.inc',
   );
   batch_set($batch);
-  batch_process($redirect, $url);
+  batch_process($redirect, $url, $redirect_callback);
 }
 
 /**