moodle/backup/backuplib.php:
...
 615         ///Roles stuff goes in here
 616 
 617         fwrite ($bf, start_tag('ROLES', 1, true));
 618         $roles = backup_fetch_roles($preferences);
 619 
 620         $sitecontext = get_context_instance(CONTEXT_SYSTEM);
 621         $coursecontext = get_context_instance(CONTEXT_COURSE, $preferences->backup_course);
 622 
 623         foreach ($roles as $role) {
 624             fwrite ($bf,start_tag('ROLE',2,true));
 625             fwrite ($bf,full_tag('ID', 3, false, $role->id));
 626             fwrite ($bf,full_tag('NAME',3,false,$role->name));
 627             fwrite ($bf,full_tag('SHORTNAME',3,false,$role->shortname));
 628         /// Calculate $role name in course
 629             $nameincourse = role_get_name($role, $coursecontext);
 630             if ($nameincourse != $role->name) {
 631                 fwrite ($bf,full_tag('NAMEINCOURSE', 3, false, $nameincourse));
 632             }
 633             // find and write all default capabilities
 634             fwrite ($bf,start_tag('CAPABILITIES',3,true));
 635             // pull out all default (site context) capabilities
 636             if ($capabilities = role_context_capabilities($role->id, $sitecontext)) {
 637                 foreach ($capabilities as $capability=>$value) {
 638                     fwrite ($bf,start_tag('CAPABILITY',4,true));
 639                     fwrite ($bf,full_tag('NAME', 5, false, $capability));
 640                     fwrite ($bf,full_tag('PERMISSION', 5, false, $value));
 641                     // use this to pull out the other info (timemodified and modifierid)
 642 
 643                     $cap = get_record_sql("SELECT *
 644                                            FROM {$CFG->prefix}role_capabilities
 645                                            WHERE capability = '$capability'
 646                                                  AND contextid = $sitecontext->id
 647                                                  AND roleid = $role->id");
 648                     fwrite ($bf, full_tag("TIMEMODIFIED", 5, false, $cap->timemodified));
 649                     fwrite ($bf, full_tag("MODIFIERID", 5, false, $cap->modifierid));
 650                     fwrite ($bf,end_tag('CAPABILITY',4,true));
 651                 }
 652             }
 653             fwrite ($bf,end_tag('CAPABILITIES',3,true));
 654             fwrite ($bf,end_tag('ROLE',2,true));
 655         }
 656         fwrite ($bf,end_tag('ROLES', 1, true));
...

moodle/backup/restorelib.php:
...
8693     /**
8694      * This function restores all the needed roles for this course
8695      * i.e. roles with an assignment in any of the mods or blocks,
8696      * roles assigned on any user (e.g. parent role) and roles
8697      * assigned at course levle
8698      * This function should check for duplicate roles first
8699      * It isn't now, just overwriting
8700      */
8701     function restore_create_roles($restore, $xmlfile) {
...
8810     /**
8811      * this function restores role assignments and role overrides
8812      * in course/user/block/mod level, it passed through
8813      * the xml file again
8814      */
8815     function restore_roles_settings($restore, $xmlfile)