Index: index.php
===================================================================
RCS file: /cvs/drupal/drupal/index.php,v
retrieving revision 1.82
diff -u -F^f -r1.82 index.php
--- index.php	21 Aug 2004 06:42:34 -0000	1.82
+++ index.php	12 Apr 2005 21:21:22 -0000
@@ -14,6 +14,7 @@
 include_once 'includes/common.inc';
 
 fix_gpc_magic();
+fix_checkboxes();
 
 $status = menu_execute_active_handler();
 switch ($status) {
Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.437
diff -u -F^f -r1.437 common.inc
--- includes/common.inc	11 Apr 2005 22:48:27 -0000	1.437
+++ includes/common.inc	12 Apr 2005 21:21:24 -0000
@@ -413,6 +413,20 @@ function fix_gpc_magic() {
 }
 
 /**
+ * Empty arrays can not be posted through HTML. So we check and fix empty
+ * form_checkboxes.
+ */
+function fix_checkboxes() {
+  if (isset($_POST['form_checkboxes'])) {
+    foreach ($_POST['form_checkboxes'] as $key) {
+      if (!array_key_exists($key, $_POST['edit'])) {
+        $_POST['edit'][$key] = array();
+      }
+    }
+  }
+}
+
+/**
  * @name Conversion
  * @{
  * Converts data structures to different types.
@@ -1177,9 +1191,8 @@ function form_checkboxes($title, $name, 
       $choices .= '<label class="option"><input type="checkbox" class="form-checkbox" name="edit['. $name .'][]" value="'. $key .'"'. (in_array($key, $values) ? ' checked="checked"' : ''). drupal_attributes($attributes) .' /> '. $choice .'</label><br />';
     }
     // Note: because unchecked boxes are not included in the POST data, we
-    // include a form_hidden() which will be overwritten as soon as there is at
-    // least one checked box.
-    return form_hidden($name, 0) . theme('form_element', $title, $choices, $description, NULL, $required, _form_get_error($name));
+    // indicate that $name is a form_checkbox.
+    return '<input type="hidden" name="form_checkboxes[]" value="'. $name.'">' . theme('form_element', $title, $choices, $description, NULL, $required, _form_get_error($name));
   }
 }