diff options
Diffstat (limited to 'includes/form.inc')
| -rw-r--r-- | includes/form.inc | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/includes/form.inc b/includes/form.inc index bec7d1e1c..846bcb51f 100644 --- a/includes/form.inc +++ b/includes/form.inc @@ -167,6 +167,12 @@ function drupal_get_form($form_id) { * processed. * - base_form_id: Identification for a base form, as declared in a * hook_forms() implementation. + * - immutable: If this flag is set to TRUE, a new form build id is + * generated when the form is loaded from the cache. If it is subsequently + * saved to the cache again, it will have another cache id and therefore + * the original form and form-state will remain unaltered. This is + * important when page caching is enabled in order to prevent form state + * from leaking between anonymous users. * - rebuild_info: Internal. Similar to 'build_info', but pertaining to * drupal_rebuild_form(). * - rebuild: Normally, after the entire form processing is completed and @@ -458,16 +464,24 @@ function drupal_rebuild_form($form_id, &$form_state, $old_form = NULL) { $form = drupal_retrieve_form($form_id, $form_state); // If only parts of the form will be returned to the browser (e.g., Ajax or - // RIA clients), re-use the old #build_id to not require client-side code to - // manually update the hidden 'build_id' input element. + // RIA clients), or if the form already had a new build ID regenerated when it + // was retrieved from the form cache, reuse the existing #build_id. // Otherwise, a new #build_id is generated, to not clobber the previous // build's data in the form cache; also allowing the user to go back to an // earlier build, make changes, and re-submit. // @see drupal_prepare_form() - if (isset($old_form['#build_id']) && !empty($form_state['rebuild_info']['copy']['#build_id'])) { + $enforce_old_build_id = isset($old_form['#build_id']) && !empty($form_state['rebuild_info']['copy']['#build_id']); + $old_form_is_mutable_copy = isset($old_form['#build_id_old']); + if ($enforce_old_build_id || $old_form_is_mutable_copy) { $form['#build_id'] = $old_form['#build_id']; + if ($old_form_is_mutable_copy) { + $form['#build_id_old'] = $old_form['#build_id_old']; + } } else { + if (isset($old_form['#build_id'])) { + $form['#build_id_old'] = $old_form['#build_id']; + } $form['#build_id'] = 'form-' . drupal_random_key(); } @@ -522,6 +536,15 @@ function form_get_cache($form_build_id, &$form_state) { } } } + // Generate a new #build_id if the cached form was rendered on a cacheable + // page. + if (!empty($form_state['build_info']['immutable'])) { + $form['#build_id_old'] = $form['#build_id']; + $form['#build_id'] = 'form-' . drupal_random_key(); + $form['form_build_id']['#value'] = $form['#build_id']; + $form['form_build_id']['#id'] = $form['#build_id']; + unset($form_state['build_info']['immutable']); + } return $form; } } @@ -534,15 +557,28 @@ function form_set_cache($form_build_id, $form, $form_state) { // 6 hours cache life time for forms should be plenty. $expire = 21600; + // Ensure that the form build_id embedded in the form structure is the same as + // the one passed in as a parameter. This is an additional safety measure to + // prevent legacy code operating directly with form_get_cache and + // form_set_cache from accidentally overwriting immutable form state. + if ($form['#build_id'] != $form_build_id) { + watchdog('form', 'Form build-id mismatch detected while attempting to store a form in the cache.', array(), WATCHDOG_ERROR); + return; + } + // Cache form structure. if (isset($form)) { if ($GLOBALS['user']->uid) { $form['#cache_token'] = drupal_get_token(); } + unset($form['#build_id_old']); cache_set('form_' . $form_build_id, $form, 'cache_form', REQUEST_TIME + $expire); } // Cache form state. + if (variable_get('cache', 0) && drupal_page_is_cacheable()) { + $form_state['build_info']['immutable'] = TRUE; + } if ($data = array_diff_key($form_state, array_flip(form_state_keys_no_cache()))) { cache_set('form_state_' . $form_build_id, $data, 'cache_form', REQUEST_TIME + $expire); } |