? sites/default/settings.php
? sites/default/files/.htaccess
? sites/default/files/simpletest
Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.304
diff -u -p -r1.304 form.inc
--- includes/form.inc	15 Nov 2008 15:32:36 -0000	1.304
+++ includes/form.inc	16 Nov 2008 00:44:21 -0000
@@ -852,7 +852,7 @@ function form_error(&$element, $message 
  *   $_POST data.
  */
 function form_builder($form_id, $form, &$form_state) {
-  static $complete_form, $cache, $file;
+  static $complete_form, $cache, $enctype, $file;
 
   // Initialize as unprocessed.
   $form['#processed'] = FALSE;
@@ -865,6 +865,7 @@ function form_builder($form_id, $form, &
 
   if (isset($form['#type']) && $form['#type'] == 'form') {
     $cache = NULL;
+    $enctype = NULL;
     $complete_form = $form;
     if (!empty($form['#programmed'])) {
       $form_state['submitted'] = TRUE;
@@ -948,14 +949,22 @@ function form_builder($form_id, $form, &
   if (isset($form['#type']) && $form['#type'] == 'file') {
     $file = TRUE;
   }
+
+  // If an element requires to set the forms content type enctype attribute, we
+  // need to store this info in a static $enctype flag to update the parent form
+  // element. E.g. For files, non-ASCII data, and binary data.
+  if (isset($form['#enctype'])) {
+    $enctype = $form['#enctype'];
+  }
+  // We are on the top form, we can copy back #cache if it's set, and set the
+  // required enctype as required.
   if (isset($form['#type']) && $form['#type'] == 'form') {
-    // We are on the top form, we can copy back #cache if it's set.
     if (isset($cache)) {
       $form['#cache'] = TRUE;
     }
     // If there is a file element, we set the form encoding.
-    if (isset($file)) {
-      $form['#attributes']['enctype'] = 'multipart/form-data';
+    if (isset($enctype)) {
+      $form['#attributes']['enctype'] = $enctype;
     }
   }
   return $form;
Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.638
diff -u -p -r1.638 system.module
--- modules/system/system.module	15 Nov 2008 08:23:07 -0000	1.638
+++ modules/system/system.module	16 Nov 2008 00:35:30 -0000
@@ -308,6 +308,7 @@ function system_elements() {
   $type['file'] = array(
     '#input' => TRUE,
     '#size' => 60,
+    '#enctype' => 'multipart/form-data',
   );