Index: lib/accesslib.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/accesslib.php,v
retrieving revision 1.575
diff -u -r1.575 accesslib.php
--- lib/accesslib.php	20 Mar 2009 07:41:49 -0000	1.575
+++ lib/accesslib.php	20 Mar 2009 08:45:25 -0000
@@ -285,7 +285,7 @@
     global $CFG, $DB;
 
     $frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
-    $base = '/'. SYSCONTEXTID .'/'. $frontpagecontext->id;
+    $base = '/'. get_system_context()->id .'/'. $frontpagecontext->id;
 
     //
     // Overrides for the role in any contexts related to the course
@@ -296,7 +296,7 @@
               JOIN {role_capabilities} rc
                    ON rc.contextid=ctx.id
              WHERE rc.roleid = ?
-                   AND (ctx.id = ".SYSCONTEXTID." OR ctx.path LIKE ?)
+                   AND (ctx.id = ".get_system_context()->id." OR ctx.path LIKE ?)
                    AND ctx.contextlevel <= ".CONTEXT_COURSE."
           ORDER BY ctx.depth, ctx.path";
     $params = array($roleid, "$base/%");
@@ -385,8 +385,8 @@
 
     if (is_null($context->path) or $context->depth == 0) {
         //this should not happen
-        $contexts = array(SYSCONTEXTID, $context->id);
-        $context->path = '/'.SYSCONTEXTID.'/'.$context->id;
+        $contexts = array(get_system_context()->id, $context->id);
+        $context->path = '/'.get_system_context()->id.'/'.$context->id;
         debugging('Context id '.$context->id.' does not have valid path, please use build_context_path()', DEBUG_DEVELOPER);
 
     } else {
@@ -625,7 +625,7 @@
             // error_log("found it!");
         return true;
     }
-    $base = '/' . SYSCONTEXTID;
+    $base = '/' . get_system_context()->id;
     while (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
         $path = $matches[1];
         if ($path === $base) {
@@ -1348,7 +1348,7 @@
      *   - below this user's RAs - limited to course level
      */
 
-    $base = "/" . SYSCONTEXTID;
+    $base = "/" . get_system_context()->id;
 
     //
     // Replace $context with the target context we will
@@ -1548,7 +1548,7 @@
 function load_user_accessdata($userid) {
     global $ACCESS,$CFG;
 
-    $base = '/'.SYSCONTEXTID;
+    $base = '/'.get_system_context()->id;
 
     $accessdata = get_user_access_sitewide($userid);
     $frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
@@ -1569,7 +1569,7 @@
     // provide "default frontpage role"
     //
     if (!empty($CFG->defaultfrontpageroleid)) {
-        $base = '/'. SYSCONTEXTID .'/'. $frontpagecontext->id;
+        $base = '/'. get_system_context()->id .'/'. $frontpagecontext->id;
         $accessdata = get_default_frontpage_role_access($CFG->defaultfrontpageroleid, $accessdata);
         if (!isset($accessdata['ra'][$base])) {
             $accessdata['ra'][$base] = array($CFG->defaultfrontpageroleid);
@@ -1622,7 +1622,7 @@
         return;
     }
 
-    $base = '/'.SYSCONTEXTID;
+    $base = '/'.get_system_context()->id;
 
     if (isguestuser()) {
         $guest = get_guest_role();
@@ -1656,7 +1656,7 @@
         // provide "default frontpage role"
         //
         if (!empty($CFG->defaultfrontpageroleid)) {
-            $base = '/'. SYSCONTEXTID .'/'. $frontpagecontext->id;
+            $base = '/'. get_system_context()->id .'/'. $frontpagecontext->id;
             $accessdata = get_default_frontpage_role_access($CFG->defaultfrontpageroleid, $accessdata);
             if (!isset($accessdata['ra'][$base])) {
                 $accessdata['ra'][$base] = array($CFG->defaultfrontpageroleid);
@@ -1945,7 +1945,7 @@
 
     // Define $context->path based on the parent
     // context. In other words... Who is your daddy?
-    $basepath  = '/' . SYSCONTEXTID;
+    $basepath  = '/' . get_system_context()->id;
     $basedepth = 1;
 
     $result = true;
@@ -2097,18 +2097,10 @@
  * @return mixed system context or null
  */
 function get_system_context($cache=true) {
-    global $DB;
+    global $DB $DB;
 
     static $cached = null;
-    if ($cache and defined('SYSCONTEXTID')) {
-        if (is_null($cached)) {
-            $cached = new object();
-            $cached->id           = SYSCONTEXTID;
-            $cached->contextlevel = CONTEXT_SYSTEM;
-            $cached->instanceid   = 0;
-            $cached->path         = '/'.SYSCONTEXTID;
-            $cached->depth        = 1;
-        }
+    if ($cache && !is_null($cached)) {
         return $cached;
     }
     try {
@@ -2148,11 +2140,10 @@
         $DB->update_record('context', $context);
     }
 
-    if (!defined('SYSCONTEXTID')) {
-        define('SYSCONTEXTID', $context->id);
-    }
-
     $cached = $context;
+    $context_cache[$context->contextlevel][$context->instanceid] = $context;
+    $context_cache_id[$context->id] = $context;
+
     return $cached;
 }
 
@@ -2488,10 +2479,6 @@
 function get_context_instance_by_id($id) {
     global $context_cache, $context_cache_id, $DB;
 
-    if ($id == SYSCONTEXTID) {
-        return get_system_context();
-    }
-
     if (isset($context_cache_id[$id])) {  // Already cached
         return $context_cache_id[$id];
     }