diff --git a/includes/form.inc b/includes/form.inc
index 3f845d38a7bb27fdf9e9b19a483084acb3700d91..c29116f257c035638baed5f542808f929f3b1da8 100644
--- a/includes/form.inc
+++ b/includes/form.inc
@@ -72,19 +72,21 @@ function drupal_get_form($form_id, &$form, $callback = NULL) {
 
   if (!isset($form['#validate'])) {
     if (function_exists($form_id .'_validate')) {
-      $form['#validate'] = array($form_id .'_validate');
+      $form['#validate'] = array($form_id .'_validate' => array());
     }
     elseif (function_exists($callback .'_validate')) {
-      $form['#validate'] = array($callback .'_validate');
+      $form['#validate'] = array($callback .'_validate' => array());
     }
   }
 
   if (!isset($form['#submit'])) {
     if (function_exists($form_id .'_submit')) {
-      $form['#submit'] = array($form_id .'_submit');
+      // we set submit here so that it can be altered but use reference for
+      // $form_values because it will change later
+      $form['#submit'] = array($form_id .'_submit' => array($form_id, &$form_values));
     }
     elseif (function_exists($callback .'_submit')) {
-      $form['#submit'] = array($callback .'_submit');
+      $form['#submit'] = array($callback .'_submit' => array($form_id, &$form_values));
     }
   }
 
@@ -121,71 +123,50 @@ function drupal_validate_form($form_id, &$form, $callback = NULL) {
     }
   }
 
-  _form_validate($form);
-
-  if (isset($form['#validate'])) {
-    foreach ($form['#validate'] as $key => $function) {
-      if (isset($form['#validation_arguments'][$key])) {
-        $function_args = array_merge(array($form_id, $form_values), $form['#validation_arguments'][$key]);
-        call_user_func_array($function, $function_args);
-      }
-      else {
-        call_user_func($function, $form_id, $form_values);
-      }
-    }
-  }
+  _form_validate($form, $form_id);
 }
 
 function drupal_submit_form($form_id, $form, $callback = NULL) {
   global $form_values;
 
   if (isset($form['#submit'])) {
-    foreach ($form['#submit'] as $key => $function) {
-      if (isset($form['#execution_arguments'][$key])) {
-        $function_args = array_merge(array($form_id, $form_values), $form['#execution_arguments'][$key]);
-        call_user_func_array($function, $function_args);
-      }
-      else {
-        call_user_func($function, $form_id, $form_values);
+    foreach ($form['#submit'] as $function => $args) {
+      if (function_exists($function)) {
+        call_user_func_array($function, $args);
       }
     }
   }
 }
 
-function _form_validate($elements) {
-
-  // Recurse through all children.
-  foreach (element_children($elements) as $key) {
-    if (isset($elements[$key]) && $elements[$key]) {
-      _form_validate($elements[$key]);
-    }
-  }
-
+function _form_validate($elements, $form_id = NULL) {
   /* Validate the current input */
-  if (!$elements['#validated'] && $elements['#input']) {
+  if (!$elements['#validated'] && ($elements['#input'] || isset($form_id))) {
     // An empty checkbox returns 0, an empty textfield returns '' so we use empty().
     // Unfortunately, empty('0') returns TRUE so we need a special check for the '0' string.
     if ($elements['#required'] && empty($elements['#value']) && $elements['#value'] !== '0') {
       form_error($elements, t('%name field is required', array('%name' => $elements['#title'])));
     }
     if (isset($elements['#validate'])) {
-      if (is_array($elements['#validate'])) {
-        foreach ($elements['#validate'] as $key => $validate) {
-          $args = is_array($elements['#validate_arguments'][$key]) ? $elements['#validate_arguments'][$key] : array();
-          if (function_exists($validate))  {
-            call_user_func_array($validate, array_merge(array($elements), $args));
-          }
+      foreach ($elements['#validate'] as $function => $args) {
+        $args = array_merge(array($elements), $args);
+        // for the full form we hand over a copy of $form_values
+        if (isset($form_id)) {
+          $args = array_merge(array($form_id, $GLOBALS['form_values']), $args);
         }
-      }
-      else {
-        $args = is_array($elements['#validate_arguments']) ? $elements['#validate_arguments'] : array();
-        if (function_exists($elements['#validate']))  {
-          call_user_func_array($elements['#validate'], array_merge(array($elements), $args));
+        if (function_exists($function))  {
+          call_user_func_array($function, $args);
         }
       }
     }
     $elements['#validated'] = TRUE;
   }
+
+  // Recurse through all children.
+  foreach (element_children($elements) as $key) {
+    if (isset($elements[$key]) && $elements[$key]) {
+      _form_validate($elements[$key]);
+    }
+  }
 }
 
 /**
@@ -287,16 +268,11 @@ function _form_builder($form_id, $form) {
 
   // Allow for elements to expand to multiple elements. Radios, checkboxes and files for instance.
   if (isset($form['#process']) && !$form['#processed']) {
-    if (is_array($form['#process'])) {
-      foreach ($form['#process'] as $process) {
-        if (function_exists($process)) {
-          $form = call_user_func($process, $form);
-        }
+    foreach ($form['#process'] as $process => $args) {
+      if (function_exists($process)) {
+        $form = call_user_func($process, array_merge($form, $args));
       }
     }
-    elseif (function_exists($form['#process'])) {
-      $form = call_user_func($form['#process'], $form);
-    }
     $form['#processed'] = TRUE;
   }
 
diff --git a/modules/filter.module b/modules/filter.module
index c22eb7bbe047d4ac056896fa3d039575556f8e56..4f793a07d89d7e228f7edfc0c01585c8cdac859c 100644
--- a/modules/filter.module
+++ b/modules/filter.module
@@ -762,7 +762,15 @@ function filter_form($value = FILTER_FORMAT_DEFAULT) {
     $form['format'] = array('#type' => 'fieldset', '#title' => t('Input format'), '#collapsible' => TRUE, '#collapsed' => TRUE, '#weight' => -16);
     // Multiple formats available: display radio buttons with tips.
     foreach ($formats as $format) {
-      $form['format'][$format->format] = array('#type' => 'radio', '#title' => $format->name, '#default_value' => $value, '#return_value' => $format->format, '#parents' => array('format'), '#description' => theme('filter_tips', _filter_tips($format->format, false)), '#validate' => 'filter_form_validate');
+      $form['format'][$format->format] = array(
+        '#type' => 'filter_format',
+        '#title' => $format->name,
+        '#default_value' => $value,
+        '#return_value' => $format->format,
+        '#parents' => array('format'),
+        '#description' => theme('filter_tips', _filter_tips($format->format, false)),
+        '#validate' => array('filter_form_validate' => array())
+      );
     }
     return $form;
   }
diff --git a/modules/filter/filter.module b/modules/filter/filter.module
index c22eb7bbe047d4ac056896fa3d039575556f8e56..4f793a07d89d7e228f7edfc0c01585c8cdac859c 100644
--- a/modules/filter/filter.module
+++ b/modules/filter/filter.module
@@ -762,7 +762,15 @@ function filter_form($value = FILTER_FORMAT_DEFAULT) {
     $form['format'] = array('#type' => 'fieldset', '#title' => t('Input format'), '#collapsible' => TRUE, '#collapsed' => TRUE, '#weight' => -16);
     // Multiple formats available: display radio buttons with tips.
     foreach ($formats as $format) {
-      $form['format'][$format->format] = array('#type' => 'radio', '#title' => $format->name, '#default_value' => $value, '#return_value' => $format->format, '#parents' => array('format'), '#description' => theme('filter_tips', _filter_tips($format->format, false)), '#validate' => 'filter_form_validate');
+      $form['format'][$format->format] = array(
+        '#type' => 'filter_format',
+        '#title' => $format->name,
+        '#default_value' => $value,
+        '#return_value' => $format->format,
+        '#parents' => array('format'),
+        '#description' => theme('filter_tips', _filter_tips($format->format, false)),
+        '#validate' => array('filter_form_validate' => array())
+      );
     }
     return $form;
   }
diff --git a/modules/system.module b/modules/system.module
index bebf6e876cf642345586a7b0180466aa1caae4db..60c6b750a2711527315d39fdbdfa66ffc324a462 100644
--- a/modules/system.module
+++ b/modules/system.module
@@ -64,12 +64,12 @@ function system_elements() {
   $type['textfield'] = array('#input' => TRUE, '#size' => 60, '#maxlength' => 128, '#autocomplete_path' => FALSE);
   $type['password'] = array('#input' => TRUE, '#size' => 30, '#maxlength' => 64);
   $type['textarea'] = array('#input' => TRUE, '#cols' => 60, '#rows' => 5);
-  $type['radios'] = array('#input' => TRUE, '#process' => 'expand_radios');
+  $type['radios'] = array('#input' => TRUE, '#process' => array('expand_radios' => array()));
   $type['radio'] = array('#input' => TRUE);
-  $type['checkboxes'] = array('#input' => TRUE, '#process' => 'expand_checkboxes', '#tree' => TRUE);
+  $type['checkboxes'] = array('#input' => TRUE, '#process' => array('expand_checkboxes' => array()), '#tree' => TRUE);
   $type['select'] = array('#input' => TRUE);
   $type['weight'] = array('#input' => TRUE, '#delta' => 10);
-  $type['date'] = array('#input' => TRUE, '#process' => 'expand_date');
+  $type['date'] = array('#input' => TRUE, '#process' => array('expand_date' => array()));
   $type['file'] = array('#input' => TRUE, '#size' => 60);
 
   // Form structure
diff --git a/modules/system/system.module b/modules/system/system.module
index bebf6e876cf642345586a7b0180466aa1caae4db..60c6b750a2711527315d39fdbdfa66ffc324a462 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -64,12 +64,12 @@ function system_elements() {
   $type['textfield'] = array('#input' => TRUE, '#size' => 60, '#maxlength' => 128, '#autocomplete_path' => FALSE);
   $type['password'] = array('#input' => TRUE, '#size' => 30, '#maxlength' => 64);
   $type['textarea'] = array('#input' => TRUE, '#cols' => 60, '#rows' => 5);
-  $type['radios'] = array('#input' => TRUE, '#process' => 'expand_radios');
+  $type['radios'] = array('#input' => TRUE, '#process' => array('expand_radios' => array()));
   $type['radio'] = array('#input' => TRUE);
-  $type['checkboxes'] = array('#input' => TRUE, '#process' => 'expand_checkboxes', '#tree' => TRUE);
+  $type['checkboxes'] = array('#input' => TRUE, '#process' => array('expand_checkboxes' => array()), '#tree' => TRUE);
   $type['select'] = array('#input' => TRUE);
   $type['weight'] = array('#input' => TRUE, '#delta' => 10);
-  $type['date'] = array('#input' => TRUE, '#process' => 'expand_date');
+  $type['date'] = array('#input' => TRUE, '#process' => array('expand_date' => array()));
   $type['file'] = array('#input' => TRUE, '#size' => 60);
 
   // Form structure