Index: commands/core/core.drush.inc
===================================================================
RCS file: /cvs/drupal/contributions/modules/drush/commands/core/core.drush.inc,v
retrieving revision 1.49
diff -u -r1.49 core.drush.inc
--- commands/core/core.drush.inc	30 Oct 2009 06:12:08 -0000	1.49
+++ commands/core/core.drush.inc	30 Oct 2009 21:02:11 -0000
@@ -149,6 +149,7 @@
     ),
     'options' => array(
       'db-url' => 'A Drupal 5/6 style database URL. Only required for initial install - not re-install.',
+      'db-prefix' => 'An optional table prefix to use for initial install.',
       'account-user' => 'uid1 name. defaults to admin',
       'account-pass' => 'uid1 pass. defaults to admin',
       'account-mail' => 'uid1 email. defaults to admin@example.com',
Index: commands/core/installcore.drush.inc
===================================================================
RCS file: /cvs/drupal/contributions/modules/drush/commands/core/installcore.drush.inc,v
retrieving revision 1.4
diff -u -r1.4 installcore.drush.inc
--- commands/core/installcore.drush.inc	30 Oct 2009 19:21:15 -0000	1.4
+++ commands/core/installcore.drush.inc	30 Oct 2009 21:02:11 -0000
@@ -105,19 +105,23 @@
   install_drupal($settings);
 }
 
-// Return a db_spec based on supplied db_url or existing settings.php.
+// Return a db_spec based on supplied db_url/db_prefix options or
+// an existing settings.php.
 function drush_core_installcore_db_spec() {
   if ($db_url = drush_get_option('db-url')) {
     // We were passed a db_url. Usually a fresh site.
-    return drush_convert_db_from_db_url($db_url);
+    $db_spec = drush_convert_db_from_db_url($db_url);
+    $db_spec['db_prefix'] = drush_get_option('db-prefix');
   }
   elseif (drush_bootstrap_max() >= DRUSH_BOOTSTRAP_DRUPAL_CONFIGURATION) {
     // We have an existing settings.php.
     drush_bootstrap(DRUSH_BOOTSTRAP_DRUPAL_CONFIGURATION);
-    return _drush_sql_get_db_spec();
+    $db_spec = _drush_sql_get_db_spec();
+    $db_spec['db_prefix'] = $GLOBALS['db_prefix'];
   }
   else {
     drush_set_error(dt('Could note determine database details.'));
     return FALSE;
   }
+  return $db_spec;
 }
\ No newline at end of file