--- a/includes/common.inc	Tue Dec 23 14:32:33 2008 +0100
+++ b/includes/common.inc	Tue Dec 23 14:32:44 2008 +0100
@@ -1,5 +1,5 @@
 <?php
-// $Id: common.inc,v 1.756.2.29 2008/10/22 19:26:01 goba Exp $
+// $Id: common.inc,v 1.756.2.35 2008/12/10 22:30:13 goba Exp $
 
 /**
  * @file
@@ -499,9 +499,8 @@
   $request = $method .' '. $path ." HTTP/1.0\r\n";
   $request .= implode("\r\n", $defaults);
   $request .= "\r\n\r\n";
-  if ($data) {
-    $request .= $data ."\r\n";
-  }
+  $request .= $data;
+
   $result->request = $request;
 
   fwrite($fp, $request);
@@ -665,7 +664,7 @@
 /**
  * Translate strings to the page language or a given language.
  *
- * All human-readable text that will be displayed somewhere within a page should
+ * Human-readable text that will be displayed somewhere within a page should
  * be run through the t() function.
  *
  * Examples:
@@ -732,7 +731,7 @@
  *   $output .= '<p>'. t('Go to the <a href="@contact-page">contact page</a>.', array('@contact-page' => url('contact'))) .'</p>';
  * @endcode
  *
- * Also avoid escaping quotation marks wherever possible.
+ * Avoid escaping quotation marks wherever possible.
  *
  * Incorrect:
  * @code
@@ -744,6 +743,101 @@
  *   $output .= t("Don't click me.");
  * @endcode
  *
+ * Because t() is designed for handling code-based strings, in almost all
+ * cases, the actual string and not a variable must be passed through t().
+ *
+ * Extraction of translations is done based on the strings contained in t()
+ * calls. If a variable is passed through t(), the content of the variable
+ * cannot be extracted from the file for translation.
+ *
+ * Incorrect:
+ * @code
+ *   $message = 'An error occurred.';
+ *   drupal_set_message(t($message), 'error');
+ *   $output .= t($message);
+ * @endcode
+ *
+ * Correct:
+ * @code
+ *   $message = t('An error occurred.');
+ *   drupal_set_message($message, 'error');
+ *   $output .= $message;
+ * @endcode
+ *
+ * The only case in which variables can be passed safely through t() is when
+ * code-based versions of the same strings will be passed through t() (or
+ * otherwise extracted) elsewhere.
+ *
+ * In some cases, modules may include strings in code that can't use t()
+ * calls. For example, a module may use an external PHP application that
+ * produces strings that are loaded into variables in Drupal for output.
+ * In these cases, module authors may include a dummy file that passes the
+ * relevant strings through t(). This approach will allow the strings to be
+ * extracted.
+ *
+ * Sample external (non-Drupal) code:
+ * @code
+ *   class Time {
+ *     public $yesterday = 'Yesterday';
+ *     public $today = 'Today';
+ *     public $tomorrow = 'Tomorrow';
+ *   }
+ * @endcode
+ *
+ * Sample dummy file.
+ * @code
+ *   // Dummy function included in example.potx.inc.
+ *   function example_potx() {
+ *     $strings = array(
+ *       t('Yesterday'),
+ *       t('Today'),
+ *       t('Tomorrow'),
+ *     );
+ *     // No return value needed, since this is a dummy function.
+ *   }
+ * @endcode
+ *
+ * Having passed strings through t() in a dummy function, it is then
+ * okay to pass variables through t().
+ *
+ * Correct (if a dummy file was used):
+ * @code
+ *   $time = new Time();
+ *   $output .= t($time->today);
+ * @endcode
+ *
+ * However tempting it is, custom data from user input or other non-code
+ * sources should not be passed through t(). Doing so leads to the following
+ * problems and errors:
+ *  - The t() system doesn't support updates to existing strings. When user
+ *    data is updated, the next time it's passed through t() a new record is
+ *    created instead of an update. The database bloats over time and any
+ *    existing translations are orphaned with each update.
+ *  - The t() system assumes any data it receives is in English. User data may
+ *    be in another language, producing translation errors.
+ *  - The "Built-in interface" text group in the locale system is used to
+ *    produce translations for storage in .po files. When non-code strings are
+ *    passed through t(), they are added to this text group, which is rendered
+ *    inaccurate since it is a mix of actual interface strings and various user
+ *    input strings of uncertain origin.
+ *
+ * Incorrect:
+ * @code
+ *   $item = item_load();
+ *   $output .= check_plain(t($item['title']));
+ * @endcode
+ *
+ * Instead, translation of these data can be done through the locale system,
+ * either directly or through helper functions provided by contributed
+ * modules.
+ * @see hook_locale()
+ *
+ * During installation, st() is used in place of t(). Code that may be called
+ * during installation or during normal operation should use the get_t()
+ * helper function.
+ * @see st()
+ * @see get_t()
+ *
  * @param $string
  *   A string containing the English string to translate.
  * @param $args
@@ -1820,7 +1914,7 @@
   $last = '';
   while ($path != $last) {
     $last = $path;
-    $path = preg_replace('`(^|/)(?!../)([^/]+)/../`', '$1', $path);
+    $path = preg_replace('`(^|/)(?!\.\./)([^/]+)/\.\./`', '$1', $path);
   }
   return 'url('. $path .')';
 }
@@ -3537,7 +3631,16 @@
 
   drupal_clear_css_cache();
   drupal_clear_js_cache();
-  system_theme_data();
+
+  // If invoked from update.php, we must not update the theme information in the
+  // database, or this will result in all themes being disabled.
+  if (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update') {
+    _system_theme_data();
+  }
+  else {
+    system_theme_data();
+  }
+
   drupal_rebuild_theme_registry();
   menu_rebuild();
   node_types_rebuild();