- Patch #684846 by effulgentsia, rfay, quicksketch, aspilicious: AJAX...

- Patch #684846 by effulgentsia, rfay, quicksketch, aspilicious: AJAX triggered by non-submit element fails if any elements are validated.

includes/ajax.inc

@@ -257,28 +257,12 @@ function ajax_get_form() {
  * The Form API #ajax property can be set both for buttons and other input
  * elements.
  *
- * ajax_process_form() defines an additional 'formPath' JavaScript setting
- * that is used by Drupal.ajax.prototype.beforeSubmit() to automatically inject
- * an additional field 'ajax_triggering_element' to the submitted form values,
- * which contains the array #parents of the element in the form structure.
- * This additional field allows ajax_form_callback() to determine which
- * element triggered the action, as non-submit form elements do not
- * provide this information in $form_state['clicked_button'], which can
- * also be used to determine triggering element, but only submit-type
- * form elements.
- *
  * This function is also the canonical example of how to implement
  * #ajax['path']. If processing is required that cannot be accomplished with
  * a callback, re-implement this function and set #ajax['path'] to the
  * enhanced function.
  */
 function ajax_form_callback() {
-  // Find the triggering element, which was set up for us on the client side.
-  if (!empty($_REQUEST['ajax_triggering_element'])) {
-    $triggering_element_path = $_REQUEST['ajax_triggering_element'];
-    // Remove the value for form validation.
-    unset($_REQUEST['ajax_triggering_element']);
-  }
   list($form, $form_state, $form_id, $form_build_id) = ajax_get_form();
 
   // Build, validate and if possible, submit the form.
@@ -288,32 +272,11 @@ function ajax_form_callback() {
   // drupal_process_form() set up.
   $form = drupal_rebuild_form($form_id, $form_state, $form_build_id);
 
-  // $triggering_element_path in a simple form might just be 'myselect', which
-  // would mean we should use the element $form['myselect']. For nested form
-  // elements we need to recurse into the form structure to find the triggering
-  // element, so we can retrieve the #ajax['callback'] from it.
-  if (!empty($triggering_element_path)) {
-    if (!isset($form['#access']) || $form['#access']) {
-      $triggering_element = $form;
-      foreach (explode('/', $triggering_element_path) as $key) {
-        if (!empty($triggering_element[$key]) && (!isset($triggering_element[$key]['#access']) || $triggering_element[$key]['#access'])) {
-          $triggering_element = $triggering_element[$key];
-        }
-        else {
-          // We did not find the $triggering_element or do not have #access,
-          // so break out and do not provide it.
-          $triggering_element = NULL;
-          break;
-        }
-      }
-    }
-  }
-  if (empty($triggering_element)) {
-    $triggering_element = $form_state['clicked_button'];
-  }
-  // Now that we have the element, get a callback if there is one.
-  if (!empty($triggering_element)) {
-    $callback = $triggering_element['#ajax']['callback'];
+  // As part of drupal_process_form(), the element that triggered the form
+  // submission is determined, and in the case of AJAX, it might not be a
+  // button. This lets us route to the appropriate callback.
+  if (!empty($form_state['triggering_element'])) {
+    $callback = $form_state['triggering_element']['#ajax']['callback'];
   }
   if (!empty($callback) && function_exists($callback)) {
     return $callback($form, $form_state);
@@ -499,13 +462,40 @@ function ajax_process_form($element, &$form_state) {
       'speed' => 'none',
       'method' => 'replace',
       'progress' => array('type' => 'throbber'),
-      'formPath' => implode('/', $element['#array_parents']),
     );
 
-    // Process special settings.
+    // Change path to url.
     $settings['url'] = isset($settings['path']) ? url($settings['path']) : url('system/ajax');
     unset($settings['path']);
-    $settings['button'] = isset($element['#executes_submit_callback']) ? array($element['#name'] => $element['#value']) : FALSE;
+
+    // Add special data to $settings['submit'] so that when this element
+    // triggers an AJAX submission, Drupal's form processing can determine which
+    // element triggered it.
+    // @see _form_element_triggered_scripted_submission()
+    if (isset($settings['trigger_as'])) {
+      // An element can add a 'trigger_as' key within #ajax to make the element
+      // submit as though another one (for example, a non-button can use this
+      // to submit the form as though a button were clicked). When using this,
+      // the 'name' key is always required to identify the element to trigger
+      // as. The 'value' key is optional, and only needed when multiple elements
+      // share the same name, which is commonly the case for buttons.
+      $settings['submit']['_triggering_element_name'] = $settings['trigger_as']['name'];
+      if (isset($settings['trigger_as']['value'])) {
+        $settings['submit']['_triggering_element_value'] = $settings['trigger_as']['value'];
+      }
+      unset($settings['trigger_as']);
+    }
+    else {
+      // Most of the time, elements can submit as themselves, in which case the
+      // 'trigger_as' key isn't needed, and the element's name is used.
+      $settings['submit']['_triggering_element_name'] = $element['#name'];
+      // If the element is a (non-image) button, its name may not identify it
+      // uniquely, in which case a match on value is also needed.
+      // @see _form_button_was_clicked()
+      if (isset($element['#button_type']) && empty($element['#has_garbage_value'])) {
+        $settings['submit']['_triggering_element_value'] = $element['#value'];
+      }
+    }
 
     // Convert a simple #ajax['progress'] string into an array.
     if (is_string($settings['progress'])) {

misc/ajax.js

@@ -98,7 +98,7 @@ Drupal.ajax = function (base, element, element_settings) {
       type: 'bar',
       message: 'Please wait...'
     },
-    button: {}
+    submit: {}
   };
 
   $.extend(this, defaults, element_settings);
@@ -121,7 +121,7 @@ Drupal.ajax = function (base, element, element_settings) {
   var ajax = this;
   var options = {
     url: ajax.url,
-    data: ajax.button,
+    data: ajax.submit,
     beforeSerialize: function (element_settings, options) {
       return ajax.beforeSerialize(element_settings, options);
     },
@@ -200,10 +200,6 @@ Drupal.ajax.prototype.beforeSubmit = function (form_values, element, options) {
   // Disable the element that received the change.
   $(this.element).addClass('progress-disabled').attr('disabled', true);
 
-  // Server-side code needs to know what element triggered the call, so it can
-  // find the #ajax binding.
-  form_values.push({ name: 'ajax_triggering_element', value: this.formPath });
-
   // Insert progressbar or throbber.
   if (this.progress.type == 'bar') {
     var progressBar = new Drupal.progressBar('ajax-progress-' + this.element.id, eval(this.progress.update_callback), this.progress.method, eval(this.progress.error_callback));

modules/file/file.module

@@ -385,12 +385,12 @@ function file_managed_file_process($element, &$form_state, $form) {
     '#weight' => -5,
   );
 
-  // Because the output of this field changes depending on the button clicked,
-  // we need to ask FAPI immediately if the remove button was clicked.
-  // It's not good that we call this private function, but
-  // $form_state['clicked_button'] is only available after this #process
-  // callback is finished.
-  if (_form_button_was_clicked($element['remove_button'], $form_state)) {
+  // @todo It is not good to call these private functions. This should be
+  //   refactored so that the file deletion happens during a submit handler,
+  //   and form changes affected by that (such as toggling the upload and remove
+  //   buttons) happens during the 2nd run of this function that is triggered by
+  //   a form rebuild: http://drupal.org/node/736298.
+  if (_form_button_was_clicked($element['remove_button'], $form_state) || _form_element_triggered_scripted_submission($element['remove_button'], $form_state)) {
     // If it's a temporary file we can safely remove it immediately, otherwise
     // it's up to the implementing module to clean up files that are in use.
     if ($element['#file'] && $element['#file']->status == 0) {

modules/overlay/overlay.module

@@ -317,8 +317,6 @@ function overlay_preprocess_toolbar(&$variables) {
  * processing, so that it's possible to close the overlay after submitting
  * a form.
  *
- * @see _form_builder_handle_input_element()
- * @see _form_builder_ie_cleanup()
  * @see form_execute_handlers()
  * @see form_builder()
  * @see overlay_form_submit()
@@ -327,17 +325,6 @@ function overlay_preprocess_toolbar(&$variables) {
  */
 function overlay_form_after_build($form, &$form_state) {
   if (overlay_get_mode() == 'child') {
-    // Form API may have already captured submit handlers from the submitted
-    // button before after_build callback is invoked. This may have been done
-    // by _form_builder_handle_input_element(). If so, the list of submit
-    // handlers is stored in the $form_state array, which is something we can
-    // also alter from here, luckily. Rememeber: our goal here is to set
-    // $form_state['redirect'] to FALSE if the API function
-    // overlay_request_dialog_close() has been invoked. That's because we want
-    // to tell the parent window to close the overlay.
-    if (!empty($form_state['submit_handlers']) && !in_array('overlay_form_submit', $form_state['submit_handlers'])) {
-      $form_state['submit_handlers'][] = 'overlay_form_submit';
-    }
     // If this element has submit handlers, then append our own.
     if (isset($form['#submit'])) {
       $form['#submit'][] = 'overlay_form_submit';

modules/poll/poll.test

@@ -341,7 +341,7 @@ class PollJSAddChoice extends DrupalWebTestCase {
 
     // Press 'add choice' button through AJAX, and place the expected HTML result
     // as the tested content.
-    $commands = $this->drupalPostAJAX(NULL, $edit, 'poll_more');
+    $commands = $this->drupalPostAJAX(NULL, $edit, array('op' => t('More choices')));
     $this->content = $commands[1]['data'];
 
     $this->assertFieldByName('choice[chid:0][chtext]', $edit['choice[new:0][chtext]'], t('Field !i found', array('!i' => 0)));

modules/simpletest/drupal_web_test_case.php

@@ -1576,11 +1576,18 @@ protected function drupalGetAJAX($path, array $options = array(), array $headers
    *     which is likely different than the $path parameter used for retrieving
    *     the initial form. Defaults to 'system/ajax'.
    *   - triggering_element: If the value for the 'path' key is 'system/ajax' or
-   *     another generic AJAX processing path, this needs to be set to the '/'
-   *     separated path to the element within the server's cached $form array.
-   *     The callback for the generic AJAX processing path uses this to find
-   *     the #ajax information for the element, including which specific
-   *     callback to use for processing the request.
+   *     another generic AJAX processing path, this needs to be set to the name
+   *     of the element. If the name doesn't identify the element uniquely, then
+   *     this should instead be an array with a single key/value pair,
+   *     corresponding to the element name and value. The callback for the
+   *     generic AJAX processing path uses this to find the #ajax information
+   *     for the element, including which specific callback to use for
+   *     processing the request.
+   *
+   *   This can also be set to NULL in order to emulate an Internet Explorer
+   *   submission of a form with a single text field, and pressing ENTER in that
+   *   textfield: under these conditions, no button information is added to the
+   *   POST data.
    * @param $options
    *   Options to be forwarded to url().
    * @param $headers
@@ -1622,7 +1629,7 @@ protected function drupalPost($path, $edit, $submit, array $options = array(), a
 
         // We post only if we managed to handle every field in edit and the
         // submit button matches.
-        if (!$edit && $submit_matches) {
+        if (!$edit && ($submit_matches || !isset($submit))) {
           $post_array = $post;
           if ($upload) {
             // TODO: cURL handles file uploads for us, but the implementation
@@ -1643,7 +1650,14 @@ protected function drupalPost($path, $edit, $submit, array $options = array(), a
               $post[$key] = urlencode($key) . '=' . urlencode($value);
             }
             if ($ajax && isset($submit['triggering_element'])) {
-              $post['ajax_triggering_element'] = 'ajax_triggering_element=' . urlencode($submit['triggering_element']);
+              if (is_array($submit['triggering_element'])) {
+                // Get the first key/value pair in the array.
+                $post['_triggering_element_value'] = '_triggering_element_value=' . urlencode(reset($submit['triggering_element']));
+                $post['_triggering_element_name'] = '_triggering_element_name=' . urlencode(key($submit['triggering_element']));
+              }
+              else {
+                $post['_triggering_element_name'] = '_triggering_element_name=' . urlencode($submit['triggering_element']);
+              }
             }
             $post = implode('&', $post);
           }
@@ -1666,7 +1680,7 @@ protected function drupalPost($path, $edit, $submit, array $options = array(), a
       foreach ($edit as $name => $value) {
         $this->fail(t('Failed to set field @name to @value', array('@name' => $name, '@value' => $value)));
       }
-      if (!$ajax) {
+      if (!$ajax && isset($submit)) {
         $this->assertTrue($submit_matches, t('Found the @submit button', array('@submit' => $submit)));
       }
       $this->fail(t('Found the requested form fields at @path', array('@path' => $path)));
@@ -1856,7 +1870,7 @@ protected function handleForm(&$post, &$edit, &$upload, $submit, $form) {
             break;
           case 'submit':
           case 'image':
-            if ($submit == $value) {
+            if (isset($submit) && $submit == $value) {
               $post[$name] = $value;
               $submit_matches = TRUE;
             }

modules/simpletest/tests/ajax.test

@@ -98,62 +98,62 @@ class AJAXCommandsTestCase extends AJAXTestCase {
     $edit = array();
 
     // Tests the 'after' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'after_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'After': Click to put something after the div"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'insert' && $command['method'] == 'after' && $command['data'] == 'This will be placed after', "'after' AJAX command issued with correct data");
 
     // Tests the 'alert' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'alert_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'Alert': Click to alert"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'alert' && $command['text'] == 'Alert', "'alert' AJAX Command issued with correct text");
 
     // Tests the 'append' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'append_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'Append': Click to append something"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'insert' && $command['method'] == 'append' && $command['data'] == 'Appended text', "'append' AJAX command issued with correct data");
 
     // Tests the 'before' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'before_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'before': Click to put something before the div"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'insert' && $command['method'] == 'before' && $command['data'] == 'Before text', "'before' AJAX command issued with correct data");
 
     // Tests the 'changed' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'changed_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX changed: Click to mark div changed."))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'changed' && $command['selector'] == '#changed_div', "'changed' AJAX command issued with correct selector");
 
     // Tests the 'changed' command using the second argument.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'changed_command_asterisk_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX changed: Click to mark div changed with asterisk."))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'changed' && $command['selector'] == '#changed_div' && $command['asterisk'] == '#changed_div_mark_this', "'changed' AJAX command (with asterisk) issued with correct selector");
 
     // Tests the 'css' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'css_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("Set the the '#box' div to be blue."))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'css' && $command['selector'] == '#css_div' && $command['argument']['background-color'] == 'blue', "'css' AJAX command issued with correct selector");
 
     // Tests the 'data' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'data_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX data command: Issue command."))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'data' && $command['name'] == 'testkey' && $command['value'] == 'testvalue', "'data' AJAX command issued with correct key and value");
 
     // Tests the 'html' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'html_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX html: Replace the HTML in a selector."))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'insert' && $command['method'] == 'html' && $command['data'] == 'replacement text', "'html' AJAX command issued with correct data");
 
     // Tests the 'prepend' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'prepend_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'prepend': Click to prepend something"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'insert' && $command['method'] == 'prepend' && $command['data'] == 'prepended text', "'prepend' AJAX command issued with correct data");
 
     // Tests the 'remove' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'remove_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'remove': Click to remove text"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'remove' && $command['selector'] == '#remove_text', "'remove' AJAX command issued with correct command and selector");
 
     // Tests the 'restripe' command.
-    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, 'restripe_command_example'));
+    $commands = $this->discardSettings($this->drupalPostAJAX($form_path, $edit, array('op' => t("AJAX 'restripe' command"))));
     $command = $commands[0];
     $this->assertTrue($command['command'] == 'restripe' && $command['selector'] == '#restripe_table', "'restripe' AJAX command issued with correct selector");
   }
@@ -203,3 +203,37 @@ class AJAXFormValuesTestCase extends AJAXTestCase {
     }
   }
 }
+
+
+/**
+ * Miscellaneous AJAX tests using ajax_test module.
+ */
+class AJAXElementValidation extends AJAXTestCase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Miscellaneous AJAX tests',
+      'description' => 'Various tests of AJAX behavior',
+      'group' => 'AJAX',
+    );
+  }
+
+  /**
+   * Try to post an AJAX change to a form that has a validated element.
+   *
+   * The drivertext field is AJAX-enabled. An additional field is not, but
+   * is set to be a required field. In this test the required field is not
+   * filled in, and we want to see if the activation of the "drivertext"
+   * AJAX-enabled field fails due to the required field being empty.
+   */
+  function testAJAXElementValidation() {
+    $web_user = $this->drupalCreateUser();
+    $edit = array('drivertext' => t('some dumb text'));
+
+    // Post with 'drivertext' as the triggering element.
+    $post_result = $this->drupalPostAJAX('ajax_validation_test', $edit, 'drivertext');
+    // Look for a validation failure in the resultant JSON.
+    $this->assertNoText(t('Error message'), t("No error message in resultant JSON"));
+    $this->assertText('ajax_forms_test_validation_form_callback invoked', t('The correct callback was invoked'));
+  }
+}
+

modules/simpletest/tests/ajax_forms_test.module

@@ -24,6 +24,12 @@ function ajax_forms_test_menu() {
     'page arguments' => array('ajax_forms_test_ajax_commands_form'),
     'access callback' => TRUE,
   );
+  $items['ajax_validation_test'] = array(
+    'title' => 'AJAX Validation Test',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('ajax_forms_test_validation_form'),
+    'access callback' => TRUE,
+  );
   return $items;
 }
 
@@ -340,3 +346,59 @@ function ajax_forms_test_advanced_commands_restripe_callback($form, $form_state)
   $commands[] = ajax_command_restripe('#restripe_table');
   return array('#type' => 'ajax', '#commands' => $commands);
 }
+
+
+
+/**
+ * This form and its related submit and callback functions demonstrate
+ * not validating another form element when a single AJAX element is triggered.
+ *
+ * The "drivertext" element is an AJAX-enabled textfield, free-form.
+ * The "required_field" element is a textfield marked required.
+ *
+ * The correct behavior is that the AJAX-enabled drivertext element should
+ * be able to trigger without causing validation of the "required_field".
+ */
+function ajax_forms_test_validation_form($form, &$form_state) {
+
+  $form['drivertext'] = array(
+    '#title' => t('AJAX-enabled textfield.'),
+    '#description' => t("When this one AJAX-triggers and the spare required field is empty, you should not get an error."),
+    '#type' => 'textfield',
+    '#default_value' => !empty($form_state['values']['drivertext']) ? $form_state['values']['drivertext'] : "",
+    '#ajax' => array(
+      'callback' => 'ajax_forms_test_validation_form_callback',
+      'wrapper' => 'message_area',
+      'method' => 'replace',
+    ),
+    '#suffix' => '<div id="message_area"></div>',
+  );
+
+  $form['spare_required_field'] = array(
+    '#title' => t("Spare Required Field"),
+    '#type' => 'textfield',
+    '#required' => TRUE,
+  );
+
+  $form['submit'] = array(
+    '#type' => 'submit',
+    '#value' => t('Submit'),
+  );
+
+  return $form;
+}
+/**
+ * Submit handler for the validation form.
+ */
+function ajax_forms_test_validation_form_submit($form, $form_state) {
+  drupal_set_message(t("Validation form submitted"));
+}
+
+/**
+ * AJAX callback for the 'drivertext' element of the validation form.
+ */
+function ajax_forms_test_validation_form_callback($form, $form_state) {
+  drupal_set_message("ajax_forms_test_validation_form_callback invoked");
+  drupal_set_message(t("Callback: drivertext=%drivertext, spare_required_field=%spare_required_field", array('%drivertext' => $form_state['values']['drivertext'], '%spare_required_field' => $form_state['values']['spare_required_field'])));
+  return '<div id="message_area">ajax_forms_test_validation_form_callback at ' . date('c') . '</div>';
+}

modules/simpletest/tests/form.test

@@ -850,6 +850,77 @@ class FormsProgrammaticTestCase extends DrupalWebTestCase {
   }
 }
 
+/**
+ * Test that FAPI correctly determines $form_state['clicked_button'].
+ */
+class FormsClickedButtonTestCase extends DrupalWebTestCase {
+
+  function getInfo() {
+    return array(
+      'name' => 'Form clicked button determination',
+      'description' => 'Test the determination of $form_state[\'clicked_button\'].',
+      'group' => 'Form API',
+    );
+  }
+
+  function setUp() {
+    parent::setUp('form_test');
+  }
+
+  /**
+   * Test the determination of $form_state['clicked_button'] when no button
+   * information is included in the POST data, as is sometimes the case when
+   * the ENTER key is pressed in a textfield in Internet Explorer.
+   */
+  function testNoButtonInfoInPost() {
+    $path = 'form-test/clicked-button';
+    $edit = array();
+    $form_id = 'form-test-clicked-button';
+
+    // Ensure submitting a form with no buttons results in no
+    // $form_state['clicked_button'] and the form submit handler not running.
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path, $edit, NULL, array(), array(), $form_id);
+    $this->assertText('There is no clicked button.', t('$form_state[\'clicked_button\'] set to NULL.'));
+    $this->assertNoText('Submit handler for form_test_clicked_button executed.', t('Form submit handler did not execute.'));
+
+    // Ensure submitting a form with one or more submit buttons results in
+    // $form_state['clicked_button'] being set to the first one the user has
+    // access to. An argument with 'r' in it indicates a restricted
+    // (#access=FALSE) button.
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path . '/s', $edit, NULL, array(), array(), $form_id);
+    $this->assertText('The clicked button is button1.', t('$form_state[\'clicked_button\'] set to only button.'));
+    $this->assertText('Submit handler for form_test_clicked_button executed.', t('Form submit handler executed.'));
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path . '/s/s', $edit, NULL, array(), array(), $form_id);
+    $this->assertText('The clicked button is button1.', t('$form_state[\'clicked_button\'] set to first button.'));
+    $this->assertText('Submit handler for form_test_clicked_button executed.', t('Form submit handler executed.'));
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path . '/rs/s', $edit, NULL, array(), array(), $form_id);
+    $this->assertText('The clicked button is button2.', t('$form_state[\'clicked_button\'] set to first available button.'));
+    $this->assertText('Submit handler for form_test_clicked_button executed.', t('Form submit handler executed.'));
+
+    // Ensure submitting a form with buttons of different types results in
+    // $form_state['clicked_button'] being set to the first button, regardless
+    // of type. For the FAPI 'button' type, this should result in the submit
+    // handler not executing. The types are 's'(ubmit), 'b'(utton), and
+    // 'i'(mage_button).
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path . '/s/b/i', $edit, NULL, array(), array(), $form_id);
+    $this->assertText('The clicked button is button1.', t('$form_state[\'clicked_button\'] set to first button.'));
+    $this->assertText('Submit handler for form_test_clicked_button executed.', t('Form submit handler executed.'));
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path . '/b/s/i', $edit, NULL, array(), array(), $form_id);
+    $this->assertText('The clicked button is button1.', t('$form_state[\'clicked_button\'] set to first button.'));
+    $this->assertNoText('Submit handler for form_test_clicked_button executed.', t('Form submit handler did not execute.'));
+    drupal_static_reset('drupal_html_id');
+    $this->drupalPost($path . '/i/s/b', $edit, NULL, array(), array(), $form_id);
+    $this->assertText('The clicked button is button1.', t('$form_state[\'clicked_button\'] set to first button.'));
+    $this->assertText('Submit handler for form_test_clicked_button executed.', t('Form submit handler executed.'));
+  }
+}
+
 
 /**
  * Tests rebuilding of arbitrary forms by altering them.

modules/simpletest/tests/form_test.module

@@ -118,6 +118,14 @@ function form_test_menu() {
     'type' => MENU_CALLBACK,
   );
 
+  $items['form-test/clicked-button'] = array(
+    'title' => 'Clicked button test',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('form_test_clicked_button'),
+    'access callback' => TRUE,
+    'type' => MENU_CALLBACK,
+  );
+
   return $items;
 }
 
@@ -923,6 +931,84 @@ function form_test_programmatic_form_submit($form, &$form_state) {
   $form_state['storage']['programmatic_form_submit'] = $form_state['values']['submitted_field'];
 }
 
+/**
+ * Form builder to test button click detection.
+ */
+function form_test_clicked_button($form, &$form_state) {
+  // A single text field. In IE, when a form has only one non-button input field
+  // and the ENTER key is pressed while that field has focus, the form is
+  // submitted without any information identifying the button responsible for
+  // the submission. In other browsers, the form is submitted as though the
+  // first button were clicked.
+  $form['text'] = array(
+    '#title' => 'Text',
+    '#type' => 'textfield',
+  );
+
+  // Loop through each path argument, addding buttons based on the information
+  // in the argument. For example, if the path is
+  // form-test/clicked-button/s/i/rb, then 3 buttons are added: a 'submit', an
+  // 'image_button', and a 'button' with #access=FALSE. This enables form.test
+  // to test a variety of combinations.
+  $i=0;
+  $args = array_slice(arg(), 2);
+  foreach ($args as $arg) {
+    $name = 'button' . ++$i;
+    // 's', 'b', or 'i' in the argument define the button type wanted.
+    if (strpos($arg, 's') !== FALSE) {
+      $type = 'submit';
+    }
+    elseif (strpos($arg, 'b') !== FALSE) {
+      $type = 'button';
+    }
+    elseif (strpos($arg, 'i') !== FALSE) {
+      $type = 'image_button';
+    }
+    else {
+      $type = NULL;
+    }
+    if (isset($type)) {
+      $form[$name] = array(
+        '#type' => $type,
+        '#name' => $name,
+      );
+      // Image buttons need a #src; the others need a #value.
+      if ($type == 'image_button') {
+        $form[$name]['#src'] = 'misc/druplicon.png';
+      }
+      else {
+        $form[$name]['#value'] = $name;
+      }
+      // 'r' for restricted, so we can test that button click detection code
+      // correctly takes #access security into account.
+      if (strpos($arg, 'r') !== FALSE) {
+        $form[$name]['#access'] = FALSE;
+      }
+    }
+  }
+
+  return $form;
+}
+
+/**
+ * Form validation handler for the form_test_clicked_button() form.
+ */
+function form_test_clicked_button_validate($form, &$form_state) {
+  if (isset($form_state['clicked_button'])) {
+    drupal_set_message(t('The clicked button is %name.', array('%name' => $form_state['clicked_button']['#name'])));
+  }
+  else {
+    drupal_set_message('There is no clicked button.');
+  }
+}
+
+/**
+ * Form submit handler for the form_test_clicked_button() form.
+ */
+function form_test_clicked_button_submit($form, &$form_state) {
+  drupal_set_message('Submit handler for form_test_clicked_button executed.');
+}
+
 
 /**
  * Implements hook_form_FORM_ID_alter() for the registration form.

modules/system/system.module

@@ -318,6 +318,7 @@ function system_element_info() {
     '#name' => 'op',
     '#button_type' => 'submit',
     '#executes_submit_callback' => TRUE,
+    '#limit_validation_errors' => FALSE,
     '#process' => array('ajax_process_form'),
     '#theme_wrappers' => array('button'),
   );
@@ -326,6 +327,7 @@ function system_element_info() {
     '#name' => 'op',
     '#button_type' => 'submit',
     '#executes_submit_callback' => FALSE,
+    '#limit_validation_errors' => FALSE,
     '#process' => array('ajax_process_form'),
     '#theme_wrappers' => array('button'),
   );
@@ -333,6 +335,7 @@ function system_element_info() {
     '#input' => TRUE,
     '#button_type' => 'submit',
     '#executes_submit_callback' => TRUE,
+    '#limit_validation_errors' => FALSE,
     '#process' => array('ajax_process_form'),
     '#return_value' => TRUE,
     '#has_garbage_value' => TRUE,