MDL-26969 assignment : clarified phpdoc and fixed whitespace.

mod/assignment/lib.php

@@ -1823,7 +1823,7 @@ class assignment_base {
      * @param int $userid int The id of the user whose submission we want or 0 in which case USER->id is used
      * @param bool $createnew boolean optional Defaults to false. If set to true a new submission object will be created in the database
      * @param bool $teachermodified student submission set if false
-     * @return object|bool The submission or false if $createnew is false.
+     * @return object|bool The submission or false (if $createnew is false and there is no existing submission).
      */
     function get_submission($userid=0, $createnew=false, $teachermodified=false) {
         global $USER, $DB;
@@ -1836,7 +1836,7 @@ class assignment_base {
 
         if ($submission) {
             return $submission;
-        } else if(!$createnew) {
+        } else if (!$createnew) {
             return false;
         }
         $newsubmission = $this->prepare_new_submission($userid, $teachermodified);