Index: mod/quiz/attempt.php
===================================================================
RCS file: /cvsroot/moodle/moodle/mod/quiz/attempt.php,v
retrieving revision 1.131.2.17
diff -u -r1.131.2.17 attempt.php
--- mod/quiz/attempt.php	30 Sep 2009 10:58:03 -0000	1.131.2.17
+++ mod/quiz/attempt.php	10 Nov 2009 17:01:10 -0000
@@ -82,9 +82,11 @@
 /// We intentionally do not check open and close times here. Instead we do it lower down.
 /// This is to deal with what happens when someone submits close to the exact moment when the quiz closes.
 
-/// Check number of attempts
-    $numberofpreviousattempts = count_records_select('quiz_attempts', "quiz = '{$quiz->id}' AND " .
-        "userid = '{$USER->id}' AND timefinish > 0 AND preview != 1");
+/// Get previous attempts of this user
+/// And also we will need 'uniqueid's of all previous attempts to avoid using one question twice
+    $previousattempts = array_keys(get_records_select('quiz_attempts', "quiz = '{$quiz->id}' AND " .
+        "userid = '{$USER->id}' AND timefinish > 0 AND preview != 1", '','uniqueid'));
+    $numberofpreviousattempts = count($previousattempts);
     if (!empty($quiz->attempts) and $numberofpreviousattempts >= $quiz->attempts) {
         print_error('nomoreattempts', 'quiz', "view.php?id={$cm->id}");
     }
@@ -264,6 +266,10 @@
         }
     }
 
+    // MDL-6340: random question should know old attempts of this user to avoid using one question twice
+    $previousattemptslist = implode(',', $previousattempts);
+    $quiz->previousattempts = $previousattemptslist;
+
     // Restore the question sessions to their most recent states
     // creating new sessions where required
     if (!$states = get_question_states($questions, $quiz, $attempt, $lastattemptid)) {
Index: question/type/random/questiontype.php
===================================================================
RCS file: /cvsroot/moodle/moodle/question/type/random/questiontype.php,v
retrieving revision 1.12.2.9
diff -u -r1.12.2.9 questiontype.php
--- question/type/random/questiontype.php	17 Feb 2009 06:14:48 -0000	1.12.2.9
+++ question/type/random/questiontype.php	10 Nov 2009 17:24:44 -0000
@@ -134,24 +134,57 @@
      * @param integer $categoryid the id of a question category.
      * @param boolean whether to include questions from subcategories.
      * @param string $questionsinuse comma-separated list of question ids to exclude from consideration.
-     * @return array of question records.
+     * @param string $avoidquestionsfromattempts comma-separated list of attempt ids of this user.
+     * @return array of question ids with less used questions placed last.
      */
-    function get_usable_questions_from_category($categoryid, $subcategories, $questionsinuse) {
+    function get_usable_questions_from_category($categoryid, $subcategories, $questionsinuse, $avoidquestionsfromattempts) {
         $this->init_qtype_lists();
         if ($subcategories) {
             $categorylist = question_categorylist($categoryid);
         } else {
             $categorylist = $categoryid;
         }
-        if (!$catrandoms = get_records_select('question',
-                "category IN ($categorylist)
-                     AND parent = 0
-                     AND hidden = 0
-                     AND id NOT IN ($questionsinuse)
-                     AND qtype NOT IN ($this->excludedqtypes)", '', 'id')) {
-            $catrandoms = array();
+
+        if (!isset($avoidquestionsfromattempts)) {
+            /// If this is first attempt for this user we simply get all question id's
+            /// that can be used in this random
+            if (!$catrandoms = get_records_select('question',
+                    "category IN ($categorylist)
+                    AND parent = 0
+                    AND hidden = 0
+                    AND id NOT IN ($questionsinuse)
+                    AND qtype NOT IN ($this->excludedqtypes)", '', 'id')) {
+                $catrandoms = array();
+            }
+            return swapshuffle(array_keys($catrandoms));
+        } else {
+            /// Get list of usable questions with question id's as keys and 
+            ///     number of previous uses by this user as value
+            $previoususes = get_records_sql_menu("SELECT q.id, COUNT(qst.id) AS numprevioususes
+                FROM mdl_question q
+                LEFT JOIN mdl_question_states qst ON qst.answer LIKE CONCAT('random', q.id, '-%')
+                WHERE q.category IN ($categorylist)
+                    AND q.parent = 0
+                    AND q.hidden = 0
+                    AND q.id NOT IN ($questionsinuse)
+                    AND qtype NOT IN ($this->excludedqtypes) 
+                    AND ((qst.attempt IS NULL) OR (qst.attempt IN ($avoidquestionsfromattempts)))
+                    AND ((qst.seq_number IS NULL) OR (qst.seq_number = 0))
+                GROUP BY q.id
+                ORDER BY numprevioususes ASC");
+
+            /// Since no question can be used twice in one attempt and we are trying hard to use 
+            ///    less used questions first there should be at most two subsequent numbers of previous uses.
+            $minusedcount = current($previoususes);
+            $minused = array_keys($previoususes, $minusedcount);
+            $maxused = array_keys($previoususes, $minusedcount + 1);
+
+            /// Now we should reshuffle questions with each number of uses separately and merge them 
+            ///    in array of question ids  placing less used questions last.
+            $catrandoms = array_merge(swapshuffle($maxused), swapshuffle($minused));
+
+            return $catrandoms;
         }
-        return $catrandoms;
     }
 
     function create_session_and_responses(&$question, &$state, $cmoptions, $attempt) {
@@ -169,16 +202,16 @@
 
         if (!isset($this->catrandoms[$question->category][$question->questiontext])) {
             $catrandoms = $this->get_usable_questions_from_category($question->category,
-                    $question->questiontext == "1", $cmoptions->questionsinuse);
-            $this->catrandoms[$question->category][$question->questiontext] = swapshuffle_assoc($catrandoms);
+                    $question->questiontext == '1', $cmoptions->questionsinuse, $cmoptions->previousattempts);
+            $this->catrandoms[$question->category][$question->questiontext] = $catrandoms;
         }
 
         while ($wrappedquestion =
                 array_pop($this->catrandoms[$question->category][$question->questiontext])) {
-            if (!ereg("(^|,)$wrappedquestion->id(,|$)", $cmoptions->questionsinuse)) {
+            if (!strpos(','.$cmoptions->questionsinuse.',', ','.$wrappedquestion.',')) {
                 /// $randomquestion is not in use and will therefore be used
                 /// as the randomquestion here...
-                $wrappedquestion = get_record('question', 'id', $wrappedquestion->id);
+                $wrappedquestion = get_record('question', 'id', $wrappedquestion);
                 $QTYPES[$wrappedquestion->qtype]
                  ->get_question_options($wrappedquestion);
                 $QTYPES[$wrappedquestion->qtype]