=== modified file 'includes/form.inc'
--- includes/form.inc	
+++ includes/form.inc	
@@ -113,7 +113,6 @@ function drupal_get_form($form_id) {
   return drupal_render_form($args[0], $form);
 }
 
-
 /**
  * Retrieves a form using a form_id, populates it with $form_values,
  * processes it, and returns any validation errors encountered. This
@@ -200,16 +199,15 @@ function drupal_retrieve_form($form_id) 
  *   The path to redirect the user to upon completion.
  */
 function drupal_process_form($form_id, &$form) {
-  global $form_values, $form_submitted, $user, $form_button_counter;
+  global $form_values, $submit_callback, $user;
   static $saved_globals = array();
   // In some scenerios, this function can be called recursively. Pushing any pre-existing
   // $form_values and form submission data lets us start fresh without clobbering work done
   // in earlier recursive calls.
-  array_push($saved_globals, array($form_values, $form_submitted, $form_button_counter));
+  array_push($saved_globals, array($form_values, $submit_callback));
 
   $form_values = array();
-  $form_submitted = FALSE;
-  $form_button_counter = array(0, 0);
+  $submit_callback = array();
 
   drupal_prepare_form($form_id, $form);
   if (($form['#programmed']) || (!empty($_POST) && (($_POST['form_id'] == $form_id) || ($_POST['form_id'] == $form['#base'])))) {
@@ -217,8 +215,8 @@ function drupal_process_form($form_id, &
     // IE does not send a button value when there is only one submit button (and no non-submit buttons)
     // and you submit by pressing enter.
     // In that case we accept a submission without button values.
-    if ((($form['#programmed']) || $form_submitted || (!$form_button_counter[0] && $form_button_counter[1])) && !form_get_errors()) {
-      $redirect = drupal_submit_form($form_id, $form);
+    if ((($form['#programmed']) || $submit_callback) && !form_get_errors()) {
+      $redirect = drupal_submit_form($form_id, $form, $submit_callback);
       if (!$form['#programmed']) {
         drupal_redirect_form($form, $redirect);
       }
@@ -227,7 +225,7 @@ function drupal_process_form($form_id, &
 
   // We've finished calling functions that alter the global values, so we can
   // restore the ones that were there before this function was called.
-  list($form_values, $form_submitted, $form_button_counter) = array_pop($saved_globals);
+  list($form_values, $submit_callback) = array_pop($saved_globals);
   return $redirect;
 }
 
@@ -306,17 +304,6 @@ function drupal_prepare_form($form_id, &
     }
   }
 
-  if (!isset($form['#submit'])) {
-    if (function_exists($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());
-    }
-    elseif (function_exists($base .'_submit')) {
-      $form['#submit'] = array($base .'_submit' => array());
-    }
-  }
-
   foreach (module_implements('form_alter') as $module) {
     $function = $module .'_form_alter';
     $function($form_id, $form);
@@ -367,24 +354,37 @@ function drupal_validate_form($form_id, 
  *   theming, and hook_form_alter functions.
  * @param $form
  *   An associative array containing the structure of the form.
+ * @param $submit_callback
+ *   An array of callback functions. The name can contain %base which will be
+ *   changed to $form_id / #base accordingly.
  * @return
  *   A string containing the path of the page to display when processing
  *   is complete.
  *
  */
-function drupal_submit_form($form_id, $form) {
+function drupal_submit_form($form_id, $form, $submit_callback) {
   global $form_values;
   $default_args = array($form_id, &$form_values);
 
-  if (isset($form['#submit'])) {
-    foreach ($form['#submit'] as $function => $args) {
-      if (function_exists($function)) {
-        $args = array_merge($default_args, (array) $args);
-        // Since we can only redirect to one page, only the last redirect will work
-        $redirect = call_user_func_array($function, $args);
-        if (isset($redirect)) {
-          $goto = $redirect;
-        }
+  // Loop through the callbacks for a given submit operation, and execute
+  // each one if it exists. If we encounter a %base, we replace that with
+  // $form_id / #base
+  foreach ($submit_callback as $function => $args) {
+    if (strpos($function, '%base') !== FALSE) {
+      if (function_exists(str_replace('%base', $form_id, $function))) {
+        $function = str_replace('%base', $form_id, $function);
+      }
+      elseif (function_exists(str_replace('%base', $form['#base'], $function))) {
+        $function = str_replace('%base', $form['#base'], $function);
+      }
+    }
+
+    if (function_exists($function)) {
+      $args = array_merge($default_args, (array) $args);
+      // Since we can only redirect to one page, only the last redirect will work
+      $redirect = call_user_func_array($function, $args);
+      if (isset($redirect)) {
+        $goto = $redirect;
       }
     }
   }
@@ -581,7 +581,7 @@ function form_error(&$element, $message 
  *   An associative array containing the structure of the form.
  */
 function form_builder($form_id, $form) {
-  global $form_values, $form_submitted, $form_button_counter;
+  global $form_values, $submit_callback;
 
   // Initialize as unprocessed.
   $form['#processed'] = FALSE;
@@ -670,13 +670,13 @@ function form_builder($form_id, $form) {
         }
       }
     }
-    if (isset($form['#executes_submit_callback'])) {
-      // Count submit and non-submit buttons
-      $form_button_counter[$form['#executes_submit_callback']]++;
-      // See if a submit button was pressed
+    if (isset($form['#button_type'])) {
+      // This is an element capable of initiating a form submit. See if it was clicked.
       if (isset($form['#post'][$form['#name']]) && $form['#post'][$form['#name']] == $form['#value']) {
         $form_submitted = $form_submitted || $form['#executes_submit_callback'];
-
+        if (isset($form['#callback'])) {
+          $submit_callback = $form['#callback'];
+        }
         // In most cases, we want to use form_set_value() to manipulate the global variables.
         // In this special case, we want to make sure that the value of this element is listed
         // in $form_variables under 'op'.
@@ -698,8 +698,10 @@ function form_builder($form_id, $form) {
 
   // Set the $form_values key that gets passed to validate and submit.
   // We call this after #process gets called so that #process has a
-  // chance to update #value if desired.
-  if (isset($form['#input']) && $form['#input']) {
+  // chance to update #value if desired. Button type input fields should
+  // only show up if they're used to submit the form, so we will ignore
+  // them here.
+  if (isset($form['#input']) && $form['#input'] && !isset($form['#button_type'])) {
     form_set_value($form, $form['#value']);
   }
 
=== modified file 'modules/node/node.module'
--- modules/node/node.module	
+++ modules/node/node.module	
@@ -1936,7 +1936,17 @@ function node_form($node, $form_values =
 
   // Add the buttons.
   $form['preview'] = array('#type' => 'button', '#value' => t('Preview'), '#weight' => 40);
-  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'), '#weight' => 45);
+  $form['submit'] = array(
+    '#type' => 'submit',
+    '#value' => t('Submit'),
+    '#weight' => 45,
+    '#callback' => array(
+      $node->type .'_node_submit_early' => array(),
+      'node_form_submit' => array(),
+      $node->type .'_node_submit' => array(),
+    ),
+  );
+
   if ($node->nid && node_access('delete', $node)) {
     $form['delete'] = array('#type' => 'button', '#value' => t('Delete'), '#weight' => 50);
   }
@@ -1949,7 +1959,7 @@ function node_form_add_preview($form) {
   global $form_values;
 
   $op = isset($form_values['op']) ? $form_values['op'] : '';
-  if ($op == $form_values['preview']) {
+  if ($op == t('Preview')) {
     drupal_validate_form($form['form_id']['#value'], $form);
     if (!form_get_errors()) {
       // We pass the global $form_values here to preserve changes made during form validation
=== modified file 'modules/system/system.module'
--- modules/system/system.module	
+++ modules/system/system.module	
@@ -66,8 +66,8 @@ function system_elements() {
 
   // Inputs
   $type['checkbox'] = array('#input' => TRUE, '#return_value' => 1);
-  $type['submit'] = array('#input' => TRUE, '#name' => 'op', '#button_type' => 'submit', '#executes_submit_callback' => TRUE);
-  $type['button'] = array('#input' => TRUE, '#name' => 'op', '#button_type' => 'submit', '#executes_submit_callback' => FALSE);
+  $type['submit'] = array('#input' => TRUE, '#name' => 'op', '#button_type' => 'submit', '#callback' => array('%base_submit' => array()));
+  $type['button'] = array('#input' => TRUE, '#name' => 'op', '#button_type' => 'submit');
   $type['textfield'] = array('#input' => TRUE, '#size' => 60, '#maxlength' => 128, '#autocomplete_path' => FALSE);
   $type['password'] = array('#input' => TRUE, '#size' => 30);
   $type['password_confirm'] = array('#input' => TRUE, '#process' => array('expand_password_confirm' => array()));
@@ -409,12 +409,13 @@ function system_admin_theme_settings() {
     '#default_value' => variable_get('admin_theme', 'bluemarine'),
   );
 
+  $form = system_settings_form($form);
   // In order to give it our own submit, we have to give it the default submit
-  // too because the presence of a #submit will prevent the default #submit
+  // too because the presence of a #callback will prevent the default submit
   // from being used. Also we want ours first.
-  $form['#submit']['system_admin_theme_submit'] = array();
-  $form['#submit']['system_settings_form_submit'] = array();
-  return system_settings_form($form);
+  $form['buttons']['submit']['#callback']['system_admin_theme_submit'] = array();
+  $form['buttons']['submit']['#callback']['system_settings_form_submit'] = array();
+  return $form;
 }