diff --git a/core/includes/file.inc b/core/includes/file.inc
index 133d64f..4cae398 100644
--- a/core/includes/file.inc
+++ b/core/includes/file.inc
@@ -1947,13 +1947,17 @@ function file_transfer($uri, $headers) {
  * If the file exists but no modules responded an AccessDeniedHttpException will
  * be thrown.If the file does not exist a NotFoundHttpException will be thrown.
  *
+ * @param string $scheme
+ *   A URI scheme, a stream is referenced as "scheme://target".
+ *
  * @see hook_file_download()
  * @see system_menu()
  */
-function file_download() {
+function file_download($scheme) {
   // Merge remaining path arguments into relative file path.
   $args = func_get_args();
-  $scheme = array_shift($args);
+  // Remove $scheme from the arguments.
+  unset($args[0]);
   $target = implode('/', $args);
   $uri = $scheme . '://' . $target;
   if (file_stream_wrapper_valid_scheme($scheme) && file_exists($uri)) {
diff --git a/core/includes/form.inc b/core/includes/form.inc
index 471db5a..7b27840 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -128,7 +128,7 @@ function drupal_get_form($form_id) {
 
   $args = func_get_args();
   // Remove $form_id from the arguments.
-  array_shift($args);
+  unset($args[0]);
   $form_state['build_info']['args'] = $args;
 
   return drupal_build_form($form_id, $form_state);
@@ -3821,8 +3821,7 @@ function theme_vertical_tabs($variables) {
  *   $args = func_get_args();
  *   // We need to remove $arg1 and $arg2 from the beginning of the array so we
  *   // are left with the keywords.
- *   array_shift($args);
- *   array_shift($args);
+ *   unset($args[0], $args[1]);
  *   // We store the user's original input in $keywords, including any slashes.
  *   $keywords = implode('/', $args);
  *
diff --git a/core/modules/taxonomy/taxonomy.pages.inc b/core/modules/taxonomy/taxonomy.pages.inc
index 879d685..1688704 100644
--- a/core/modules/taxonomy/taxonomy.pages.inc
+++ b/core/modules/taxonomy/taxonomy.pages.inc
@@ -111,8 +111,8 @@ function taxonomy_autocomplete($field_name, $tags_typed = '') {
   // If the request has a '/' in the search text, then the menu system will have
   // split it into multiple arguments, recover the intended $tags_typed.
   $args = func_get_args();
-  // Shift off the $field_name argument.
-  array_shift($args);
+  // Remove $field_name from the arguments.
+  unset($args[0]);
   $tags_typed = implode('/', $args);
 
   // Make sure the field exists and is a taxonomy field.