Index: lib/moodlelib.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/moodlelib.php,v
retrieving revision 1.991
diff -u -r1.991 moodlelib.php
--- lib/moodlelib.php	26 Jan 2008 17:00:03 -0000	1.991
+++ lib/moodlelib.php	30 Jan 2008 17:51:39 -0000
@@ -1912,9 +1912,16 @@
             }
         }    
         
-    /// Non-guests who don't currently have access, check if they can be allowed in as a guest
 
+    /// Non-guests who don't currently have access...
         if ($USER->username != 'guest' and !has_capability('moodle/course:view', $COURSE->context)) {
+        /// Is it because they have a role which hasn't started yet?
+            if($inactive=get_inactive_role_on_context($COURSE->context->id)) {
+            /// Display info about the start date and stop
+                notice(get_string('courserolenotstarted','',userdate($inactive->timestart)), $CFG->wwwroot .'/');
+            }
+
+        /// Check if they can be allowed in as a guest
             if ($COURSE->guest == 1) {
                  // Temporarily assign them guest role for this context, if it fails later user is asked to enrol
                  $USER->access = load_temp_role($COURSE->context, $CFG->guestroleid, $USER->access);
Index: lib/accesslib.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/accesslib.php,v
retrieving revision 1.464
diff -u -r1.464 accesslib.php
--- lib/accesslib.php	25 Jan 2008 00:53:01 -0000	1.464
+++ lib/accesslib.php	30 Jan 2008 17:51:38 -0000
@@ -501,6 +501,7 @@
               ON ra.roleid=rc.roleid AND ra.contextid=ctx.id
             WHERE ctx.contextlevel=10
               AND ra.userid={$userid}
+              AND ra.active=1
               AND rc.capability IN ('moodle/site:config', 'moodle/legacy:admin', 'moodle/site:doanything')       
             GROUP BY rc.capability
             HAVING SUM(rc.permission) > 0";
@@ -992,7 +993,7 @@
                 JOIN {$CFG->prefix}context ctx 
                   ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
                 LEFT OUTER JOIN {$CFG->prefix}role_assignments ra
-                  ON (ra.contextid=ctx.id AND ra.userid=$userid)
+                  ON (ra.contextid=ctx.id AND ra.userid=$userid AND ra.active=1)
                 LEFT OUTER JOIN {$CFG->prefix}role_capabilities rc
                   ON (rc.contextid=ctx.id AND (rc.capability='$cap' $capany))
                 WHERE    ra.id IS NOT NULL
@@ -1247,6 +1248,7 @@
             LEFT OUTER JOIN {$CFG->prefix}role_capabilities rc
                ON (rc.roleid=ra.roleid AND rc.contextid=ra.contextid)
             WHERE ra.userid = $userid AND ctx.contextlevel <= ".CONTEXT_COURSE."
+              AND ra.active=1
             ORDER BY ctx.depth, ctx.path";
     $rs = get_recordset_sql($sql);
     //
@@ -1346,6 +1348,7 @@
             JOIN {$CFG->prefix}role_capabilities rco
               ON (rco.roleid=ra.roleid AND rco.contextid=sctx.id)
             WHERE ra.userid = $userid
+                  AND ra.active = 1
                   AND sctx.contextlevel <= ".CONTEXT_COURSE."
             ORDER BY sctx.depth, sctx.path, ra.roleid";
 
@@ -1418,6 +1421,7 @@
             JOIN {$CFG->prefix}context ctx
                ON ra.contextid=ctx.id
             WHERE ra.userid = $userid
+                  AND ra.active = 1
                   AND (ctx.path = '{$context->path}' OR ctx.path LIKE '{$context->path}/%')
             ORDER BY ctx.depth, ctx.path";
     $rs = get_recordset_sql($sql);
@@ -2908,6 +2912,11 @@
     /// by repeating queries with the same exact parameters in a 100 secs time window
         $newra->timestart = round($timestart, -2);
         $newra->timeend = $timeend;
+    /// If timestart is in the future then the role must be set to not be active
+    /// (otherwise, database defaults to active=1); will be activated later in cron
+        if($timestart > time()) {
+            $newra->active = 0; 
+        }
         $newra->timemodified = $timemodified;
         $newra->modifierid = empty($USER->id) ? 0 : $USER->id;
 
@@ -2922,6 +2931,11 @@
     /// by repeating queries with the same exact parameters in a 100 secs time window
         $newra->timestart = round($timestart, -2);
         $newra->timeend = $timeend;
+    /// If timestart is in the future then the role must be set to not be active
+    /// (otherwise, database defaults to active=1); will be activated later in cron
+        if($timestart > time()) {
+            $newra->active = 0; 
+        }
         $newra->timemodified = $timemodified;
         $newra->modifierid = empty($USER->id) ? 0 : $USER->id;
 
@@ -4070,6 +4084,7 @@
                              WHERE ra.userid = '.$userid.
                            '   AND ra.roleid = r.id
                                AND ra.contextid = c.id
+                               AND ra.active = 1
                                AND '.$contexts . $hiddensql .
                            ' ORDER BY '.$order);
 }
@@ -4994,6 +5009,35 @@
 }
 
 /**
+ * If the user has any role on the specified (exact) context which is not
+ * yet active, then we return the timestart of the role assignment.
+ * - If they have two such roles then we return the earliest timestart.
+ * - Note that they may have other active roles. This function is intended
+ *   to be used after a has_capability fails, so that information can be
+ *   displayed to the user about when they might have access again.
+ * @param int $contextid ID of context
+ * @param int $userid User ID, leave out for current user
+ * @return False if none, or an object containing fields from role_assignments
+ *   (including timestart).
+ */
+function get_inactive_role_on_context($contextid,$userid=0) {
+    global $CFG,$USER;
+    if(!$userid) {
+        $userid=$USER->id;
+    }
+    $rs=get_recordset_sql("SELECT ra.*
+                       FROM {$CFG->prefix}role_assignments ra
+                       WHERE ra.userid=$userid 
+                             AND ra.contextid=$contextid
+                             AND ra.active=0
+                             AND ra.timestart<>0
+                       ORDER BY ra.timestart");
+    $firstresult=rs_fetch_next_record($rs);
+    rs_close($rs);
+    return $firstresult; // False if no records, or the first record
+}
+
+/**
  * Switches the current user to another role for the current session and only
  * in the given context.
  *
Index: version.php
===================================================================
RCS file: /cvsroot/moodle/moodle/version.php,v
retrieving revision 1.575
diff -u -r1.575 version.php
--- version.php	29 Jan 2008 05:54:42 -0000	1.575
+++ version.php	30 Jan 2008 17:51:36 -0000
@@ -6,7 +6,7 @@
 // This is compared against the values stored in the database to determine
 // whether upgrades should be performed (see lib/db/*.php)
 
-    $version = 2007101508;  // YYYYMMDD = date
+    $version = 2008013000;  // YYYYMMDD = date
                             //       XY = increments within a single day
 
     $release = '2.0 dev';   // Human-friendly version name
Index: lang/en_utf8/moodle.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lang/en_utf8/moodle.php,v
retrieving revision 1.167
diff -u -r1.167 moodle.php
--- lang/en_utf8/moodle.php	30 Jan 2008 16:34:04 -0000	1.167
+++ lang/en_utf8/moodle.php	30 Jan 2008 17:51:37 -0000
@@ -292,6 +292,7 @@
 $string['courserequestreason'] = 'Reasons for wanting this course';
 $string['courserequestsuccess'] = 'Successfully saved your course request. Expect an email within a few days with the outcome';
 $string['courserestore'] = 'Course restore';
+$string['courserolenotstarted'] = 'You don\'t yet have access to this course. Your access should be enabled shortly after $a - please try again then.';
 $string['courses'] = 'Courses';
 $string['coursescategory'] = 'Courses in the same category';
 $string['coursespending'] = 'Courses pending approval';
Index: lib/db/upgrade.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/db/upgrade.php,v
retrieving revision 1.175
diff -u -r1.175 upgrade.php
--- lib/db/upgrade.php	29 Jan 2008 05:54:42 -0000	1.175
+++ lib/db/upgrade.php	30 Jan 2008 17:51:40 -0000
@@ -2694,6 +2694,19 @@
         upgrade_main_savepoint($result, 2007101508);
     }
 
+    if ($result && $oldversion < 2008013000) {
+
+    /// Define field active to be added to role_assignments
+        $table = new XMLDBTable('role_assignments');
+        $field = new XMLDBField('active');
+        $field->setAttributes(XMLDB_TYPE_INTEGER, '1', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null, null, '1', 'sortorder');
+
+    /// Launch add field active
+        $result = $result && add_field($table, $field);
+
+    /// Main savepoint reached
+        upgrade_main_savepoint($result, 2008013000);
+    }
 
     return $result;
 }
Index: lib/db/install.xml
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/db/install.xml,v
retrieving revision 1.137
diff -u -r1.137 install.xml
--- lib/db/install.xml	15 Dec 2007 00:49:05 -0000	1.137
+++ lib/db/install.xml	30 Jan 2008 17:51:40 -0000
@@ -819,7 +819,8 @@
         <FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="timeend" NEXT="modifierid"/>
         <FIELD NAME="modifierid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="timemodified" NEXT="enrol"/>
         <FIELD NAME="enrol" TYPE="char" LENGTH="20" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="modifierid" NEXT="sortorder"/>
-        <FIELD NAME="sortorder" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="enrol"/>
+        <FIELD NAME="sortorder" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="enrol" NEXT="active"/>
+        <FIELD NAME="active" TYPE="int" LENGTH="1" NOTNULL="true" UNSIGNED="true" DEFAULT="1" SEQUENCE="false" ENUM="false" COMMENT="Set to 0 initially for users with a timestart in the future. Updated to 1 in cron. When set to 0, this user should not have access to the permissions of the assigned role, although the role assignment may still be displayed in lists of users etc." PREVIOUS="sortorder"/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id" NEXT="roleid"/>
Index: admin/cron.php
===================================================================
RCS file: /cvsroot/moodle/moodle/admin/cron.php,v
retrieving revision 1.131
diff -u -r1.131 cron.php
--- admin/cron.php	13 Jan 2008 18:46:55 -0000	1.131
+++ admin/cron.php	30 Jan 2008 17:51:36 -0000
@@ -189,6 +189,10 @@
     }
 
 
+    mtrace('Activating any enrolments with start times ...');
+    execute_sql("UPDATE {$CFG->prefix}role_assignments SET active=1 WHERE active=0 AND timestart<".time(),false);
+    mtrace('done.');
+
     mtrace('Starting main gradebook job ...');
     grade_cron();
     mtrace('done.');