diff options
Diffstat (limited to 'includes/common.inc')
| -rw-r--r-- | includes/common.inc | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/includes/common.inc b/includes/common.inc index 8c47f0036..353010634 100644 --- a/includes/common.inc +++ b/includes/common.inc @@ -2832,8 +2832,25 @@ function drupal_system_listing($mask, $directory, $key = 'name', $min_depth = 1) * hook_$type_alter functions. */ function drupal_alter($type, &$data) { + // PHP's func_get_args() always returns copies of params, not references, so + // drupal_alter() can only manipulate data that comes in via the required first + // param. For the edge case functions that must pass in an arbitrary number of + // alterable parameters (hook_form_alter() being the best example), an array of + // those params can be placed in the __drupal_alter_by_ref key of the $data + // array. This is somewhat ugly, but is an unavoidable consequence of a flexible + // drupal_alter() function, and the limitations of func_get_args(). + // @todo: Remove this in Drupal 7. + if (isset($data['__drupal_alter_by_ref'])) { + $by_ref_parameters = $data['__drupal_alter_by_ref']; + unset($data['__drupal_alter_by_ref']); + } + // Hang onto a reference to the data array so that it isn't blown away later. + // Also, merge in any parameters that need to be passed by reference. $args = array(&$data); + if (isset($by_ref_parameters)) { + $args = array_merge($args, $by_ref_parameters); + } // Now, use func_get_args() to pull in any additional parameters passed into // the drupal_alter() call. |