Check for USER->email in require_login. With external authentication

schemes it's possible that the email field could be empty, so this
will force users to update it (and the rest of their profile) any
time they log into a course.

lib/moodlelib.php

@@ -1005,6 +1005,13 @@ function require_login($courseid=0) {
             if (!isset($USER->realuser)) {  // Don't update if this isn't a realuser
                 update_user_in_db();
             }
+            if (!$USER->email) {            // User logged in, but has not set up profile!
+                                            // This can occur with external authentication
+                $USER->email = "spam";      // To prevent auth loops
+                save_session("USER");
+                redirect("$CFG->wwwroot/user/edit.php?id=$USER->id&course=$courseid");
+                die;
+            }
             return;   // user is a member of this course.
         }
         if (! $course = get_record("course", "id", $courseid)) {