Index: modules/simpletest/tests/session.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/session.test,v
retrieving revision 1.34
diff -u -p -r1.34 session.test
--- modules/simpletest/tests/session.test	5 Nov 2010 19:05:02 -0000	1.34
+++ modules/simpletest/tests/session.test	13 Nov 2010 09:04:49 -0000
@@ -223,6 +223,33 @@ class SessionTestCase extends DrupalWebT
   }
 
   /**
+   * Test that empty session IDs are not allowed.
+   */
+  function testEmptySessionID() {
+    $user = $this->drupalCreateUser(array('access content'));
+    $this->drupalLogin($user);
+    $this->drupalGet('session-test/is-logged-in');
+    $this->assertResponse(200, t('User is logged in.'));
+
+    // Reset the sid in {sessions} to a blank string. This may exist in the
+    // wild in some cases, although we normally prevent it from happening.
+    db_query("UPDATE {sessions} SET sid = '' WHERE uid = :uid", array(':uid' => $user->uid));
+    $sid = db_query('SELECT sid FROM {sessions} WHERE uid = :uid', array(':uid' => $user->uid))->fetchField();
+    $this->assertIdentical($sid, '', t('Session ID in {sessions} is blank.'));
+
+    // Send a blank sid in the session cookie, and the session should no longer
+    // be valid. Closing the curl handler will stop the previous session ID
+    // from persisting.
+    $this->curlClose();
+    $this->additionalCurlOptions[CURLOPT_COOKIE] = rawurlencode($this->session_name) . '=;';
+    $this->drupalGet('session-test/id-from-cookie');
+    $this->assertRaw("session_id:\n", t('Session ID is blank as sent from cookie header.'));
+    // Assert that we have an anonymous session now.
+    $this->drupalGet('session-test/is-logged-in');
+    $this->assertResponse(403, t('An empty session ID is not allowed.'));
+  }
+
+  /**
    * Reset the cookie file so that it refers to the specified user.
    *
    * @param $uid User id to set as the active session.
Index: modules/simpletest/tests/session_test.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/session_test.module,v
retrieving revision 1.15
diff -u -p -r1.15 session_test.module
--- modules/simpletest/tests/session_test.module	4 Dec 2009 16:49:47 -0000	1.15
+++ modules/simpletest/tests/session_test.module	13 Nov 2010 09:04:49 -0000
@@ -17,6 +17,12 @@ function session_test_menu() {
     'access arguments' => array('access content'),
     'type' => MENU_CALLBACK,
   );
+  $items['session-test/id-from-cookie'] = array(
+    'title' => 'Session ID from cookie',
+    'page callback' => '_session_test_id_from_cookie',
+    'access arguments' => array('access content'),
+    'type' => MENU_CALLBACK,
+  );
   $items['session-test/set/%'] = array(
     'title' => 'Set session value',
     'page callback' => '_session_test_set',
@@ -49,6 +55,12 @@ function session_test_menu() {
     'access arguments' => array('access content'),
     'type' => MENU_CALLBACK,
   );
+  $items['session-test/is-logged-in'] = array(
+    'title' => 'Check if user is logged in',
+    'page callback' => '_session_test_is_logged_in',
+    'access callback' => 'user_is_logged_in',
+    'type' => MENU_CALLBACK,
+  );
 
   return $items;
 }
@@ -104,6 +116,13 @@ function _session_test_id() {
 }
 
 /**
+ * Menu callback: print the current session ID as read from the cookie.
+ */
+function _session_test_id_from_cookie() {
+  return 'session_id:' . $_COOKIE[session_name()] . "\n";
+}
+
+/**
  * Menu callback, sets a message to me displayed on the following page.
  */
 function _session_test_set_message() {
@@ -165,3 +184,10 @@ function session_test_drupal_goto_alter(
     $path = $base_insecure_url . '/' . $path;
   }
 }
+
+/**
+ * Menu callback, only available if current user is logged in.
+ */
+function _session_test_is_logged_in() {
+  return t('User is logged in.');
+}