commit b3e592c6a52827571ef822fb0a80d3720b5dbbe7
Author: Damien Tournoud <damien@commerceguys.com>
Date:   Thu Jun 23 06:45:23 2011 +0200

    Issue #1198956: allow passing additional form parameters to installation profiles.

diff --git a/commands/core/drupal/site_install.inc b/commands/core/drupal/site_install.inc
index bcec7f3..26e4464 100644
--- a/commands/core/drupal/site_install.inc
+++ b/commands/core/drupal/site_install.inc
@@ -3,7 +3,7 @@
 /**
  * Install Drupal 7+
  */
-function drush_core_site_install_version($profile) {
+function drush_core_site_install_version($profile, array $additional_form_options = array()) {
   if (is_null($profile)) {
     $profile = 'standard';
   }
@@ -46,6 +46,16 @@ function drush_core_site_install_version($profile) {
       ),
     ),
   );
+
+  // Merge in the additional options.
+  foreach ($additional_form_options as $key => $value) {
+    $current = &$settings['forms'];
+    foreach (explode('.', $key) as $param) {
+      $current = &$current[$param];
+    }
+    $current = $value;
+  }
+
   drush_log(dt('Starting Drupal installation. This takes a few seconds ...'), 'ok');
   install_drupal($settings);
   drush_log(dt('Installation complete.  User name: @name  User password: @pass', array('@name' => $account_name, '@pass' => $account_pass)), 'ok');
diff --git a/commands/core/site_install.drush.inc b/commands/core/site_install.drush.inc
index d8fc2b1..a8e084d 100644
--- a/commands/core/site_install.drush.inc
+++ b/commands/core/site_install.drush.inc
@@ -113,8 +113,22 @@ function drush_core_pre_site_install() {
  * Command callback.
  */
 function drush_core_site_install($profile = NULL) {
+  $args = func_get_args();
+  if ($args) {
+    // The first argument is the profile.
+    $profile = array_shift($args);
+    // Subsequent arguments are additional form values.
+    foreach ($args as $arg) {
+      list($key, $value) = explode('=', $arg);
+      $form_options[$key] = $value;
+    }
+  }
+  else {
+    $form_options = array();
+  }
+
   drush_include_engine('drupal', 'site_install', drush_drupal_major_version());
-  drush_core_site_install_version($profile);
+  drush_core_site_install_version($profile, $form_options);
 }
 
 /**