Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.1177
diff -u -p -r1.1177 common.inc
--- includes/common.inc	17 Jun 2010 13:44:44 -0000	1.1177
+++ includes/common.inc	20 Jun 2010 13:07:40 -0000
@@ -3602,10 +3602,15 @@ function drupal_add_js($data = NULL, $op
     // Add jquery.js and drupal.js, as well as the basePath setting, the
     // first time a Javascript file is added.
     if (empty($javascript)) {
+      // url() generates the prefix using hook_url_outbound_alter(). Instead of
+      // running the drupal_alter('url_outbound') again here, extract the prefix
+      // from url().
+      url('', array('prefix' => &$prefix));
       $javascript = array(
         'settings' => array(
           'data' => array(
             array('basePath' => base_path()),
+            array('pathPrefix' => empty($prefix) ? '' : $prefix),
           ),
           'type' => 'setting',
           'scope' => 'header',
Index: modules/overlay/overlay-parent.js
===================================================================
RCS file: /cvs/drupal/drupal/modules/overlay/overlay-parent.js,v
retrieving revision 1.48
diff -u -p -r1.48 overlay-parent.js
--- modules/overlay/overlay-parent.js	13 Jun 2010 05:47:47 -0000	1.48
+++ modules/overlay/overlay-parent.js	20 Jun 2010 13:07:40 -0000
@@ -307,8 +307,9 @@ Drupal.overlay.isAdminLink = function (u
 
   // Turn the list of administrative paths into a regular expression.
   if (!this.adminPathRegExp) {
-    var adminPaths = '^(' + Drupal.settings.overlay.paths.admin.replace(/\s+/g, ')$|^(') + ')$';
-    var nonAdminPaths = '^(' + Drupal.settings.overlay.paths.non_admin.replace(/\s+/g, ')$|^(') + ')$';
+    var regExpPrefix = '^' + Drupal.settings.pathPrefix + '(';
+    var adminPaths = regExpPrefix + Drupal.settings.overlay.paths.admin.replace(/\s+/g, ')$|' + regExpPrefix) + ')$';
+    var nonAdminPaths = regExpPrefix + Drupal.settings.overlay.paths.non_admin.replace(/\s+/g, ')$|'+ regExpPrefix) + ')$';
     adminPaths = adminPaths.replace(/\*/g, '.*');
     nonAdminPaths = nonAdminPaths.replace(/\*/g, '.*');
     this.adminPathRegExp = new RegExp(adminPaths);
Index: modules/simpletest/tests/ajax.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/ajax.test,v
retrieving revision 1.11
diff -u -p -r1.11 ajax.test
--- modules/simpletest/tests/ajax.test	30 Apr 2010 08:07:55 -0000	1.11
+++ modules/simpletest/tests/ajax.test	20 Jun 2010 13:07:40 -0000
@@ -47,6 +47,9 @@ class AJAXFrameworkTestCase extends AJAX
     $this->assertIdentical($result[0]['command'], 'settings', t('drupal_add_js() settings are contained first.'));
     // Verify that basePath is contained in JavaScript settings.
     $this->assertEqual($result[0]['settings']['basePath'], base_path(), t('Base path is contained in JavaScript settings.'));
+    // Verify that pathPrefix is contained in JavaScript settings.
+    url('', array('prefix' => &$prefix));
+    $this->assertEqual($result[0]['settings']['pathPrefix'], empty($prefix) ? '' : $prefix, t('Path prefix is contained in JavaScript settings.'));
   }
 
   /**
Index: modules/simpletest/tests/common.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/common.test,v
retrieving revision 1.113
diff -u -p -r1.113 common.test
--- modules/simpletest/tests/common.test	17 Jun 2010 13:16:57 -0000	1.113
+++ modules/simpletest/tests/common.test	20 Jun 2010 13:07:40 -0000
@@ -1098,6 +1098,8 @@ class JavaScriptTestCase extends DrupalW
     $this->assertTrue(array_key_exists('misc/drupal.js', $javascript), t('Drupal.js is added when file is added.'));
     $this->assertTrue(array_key_exists('misc/collapse.js', $javascript), t('JavaScript files are correctly added.'));
     $this->assertEqual(base_path(), $javascript['settings']['data'][0]['basePath'], t('Base path JavaScript setting is correctly set.'));
+    url('', array('prefix' => &$prefix));
+    $this->assertEqual(empty($prefix) ? '' : $prefix, $javascript['settings']['data'][1]['pathPrefix'], t('Path prefix JavaScript setting is correctly set.'));
   }
 
   /**
@@ -1105,8 +1107,8 @@ class JavaScriptTestCase extends DrupalW
    */
   function testAddSetting() {
     $javascript = drupal_add_js(array('drupal' => 'rocks', 'dries' => 280342800), 'setting');
-    $this->assertEqual(280342800, $javascript['settings']['data'][1]['dries'], t('JavaScript setting is set correctly.'));
-    $this->assertEqual('rocks', $javascript['settings']['data'][1]['drupal'], t('The other JavaScript setting is set correctly.'));
+    $this->assertEqual(280342800, $javascript['settings']['data'][2]['dries'], t('JavaScript setting is set correctly.'));
+    $this->assertEqual('rocks', $javascript['settings']['data'][2]['drupal'], t('The other JavaScript setting is set correctly.'));
   }
 
   /**
@@ -1125,6 +1127,7 @@ class JavaScriptTestCase extends DrupalW
     drupal_add_js(array('testSetting' => 'testValue'), 'setting');
     $javascript = drupal_get_js('header');
     $this->assertTrue(strpos($javascript, 'basePath') > 0, t('Rendered JavaScript header returns basePath setting.'));
+    $this->assertTrue(strpos($javascript, 'pathPrefix') > 0, t('Rendered JavaScript header returns pathPrefix setting.'));
     $this->assertTrue(strpos($javascript, 'testSetting') > 0, t('Rendered JavaScript header returns custom setting.'));
     $this->assertTrue(strpos($javascript, 'misc/jquery.js') > 0, t('Rendered JavaScript header includes jQuery.'));
   }