#109326: #id attribute not output for buttons.

includes/form.inc

@@ -1332,7 +1332,7 @@ function theme_submit($element) {
 }
 
 function theme_button($element) {
-  //Make sure not to overwrite classes
+  // Make sure not to overwrite classes.
   if (isset($element['#attributes']['class'])) {
     $element['#attributes']['class'] = 'form-'. $element['#button_type'] .' '. $element['#attributes']['class'];
   }
@@ -1340,7 +1340,7 @@ function theme_button($element) {
     $element['#attributes']['class'] = 'form-'. $element['#button_type'];
   }
 
-  return '<input type="submit" '. (empty($element['#name']) ? '' : 'name="'. $element['#name'] .'" ') .'value="'. check_plain($element['#value']) .'" '. drupal_attributes($element['#attributes']) ." />\n";
+  return '<input type="submit" '. (empty($element['#name']) ? '' : 'name="'. $element['#name'] .'" ')  .'id="'. $element['#id'].'" value="'. check_plain($element['#value']) .'" '. drupal_attributes($element['#attributes']) ." />\n";
 }
 
 /**