1 files changed, 4 insertions, 1 deletions
diff --git a/install.php b/install.php
index b2da561f6..f5719a1cd 100644
--- a/install.php
+++ b/install.php
@@ -386,7 +386,10 @@ function install_run_task($task, &$install_state) {
       // redirect, since the installer handles its own redirection only after
       // marking the form submission task complete.
       $form_state = array(
-        'args' => array($install_state),
+        // We need to pass $install_state by reference in order for forms to
+        // modify it, since the form API will use it in call_user_func_array(),
+        // which requires that referenced variables be passed explicitly.
+        'args' => array(&$install_state),
         'no_redirect' => TRUE,
       );
       $form = drupal_build_form($function, $form_state);