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	5 Nov 2009 18:36:45 -0000
@@ -264,6 +264,11 @@
         }
     }
 
+    // MDL-6340: random question should know old attempts of this user to avoid using one question twice
+    $oldattempts = array_keys(get_records_select('quiz_attempts', "userid=$USER->id AND attempt<>$attempt->attempt", '','uniqueid'));
+    $oldattemptslist = implode(',', $oldattempts);
+    $quiz->oldattempts = $oldattemptslist;
+
     // Restore the question sessions to their most recent states
     // creating new sessions where required
     if (!$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	5 Nov 2009 19:37:39 -0000
@@ -136,22 +136,41 @@
      * @param string $questionsinuse comma-separated list of question ids to exclude from consideration.
      * @return array of question records.
      */
-    function get_usable_questions_from_category($categoryid, $subcategories, $questionsinuse) {
+    function get_usable_questions_from_category($categoryid, $subcategories, $cmoptions) {
         $this->init_qtype_lists();
         if ($subcategories) {
             $categorylist = question_categorylist($categoryid);
         } else {
             $categorylist = $categoryid;
         }
+
+        // Get id`s of questions that was used in previous attempts
+        $usedanswers = get_records_select('question_states', "attempt IN ($cmoptions->oldattempts)", '', 'answer');
+        foreach ($usedanswers as $answer) {
+            ereg('^random([0-9]+)-', $answer->answer, $cmpresult);
+            $usedids[]=$cmpresult[1];
+        }
+        $usedlist = implode(',', $usedids);
+
         if (!$catrandoms = get_records_select('question',
                 "category IN ($categorylist)
                      AND parent = 0
                      AND hidden = 0
-                     AND id NOT IN ($questionsinuse)
+                     AND id NOT IN ($cmoptions->questionsinuse)
+                     AND id NOT IN ($usedlist)
                      AND qtype NOT IN ($this->excludedqtypes)", '', 'id')) {
-            $catrandoms = array();
+            // If all questions was used in previous attempts fallback to all questions
+            if (!$catrandoms = get_records_select('question',
+                    "category IN ($categorylist)
+                        AND parent = 0
+                        AND hidden = 0
+                        AND id NOT IN ($cmoptions->questionsinuse)
+                        AND qtype NOT IN ($this->excludedqtypes)", '', 'id')) {
+                $catrandoms = array();
+            }
         }
-        return $catrandoms;
+
+        return array_keys($catrandoms);
     }
 
     function create_session_and_responses(&$question, &$state, $cmoptions, $attempt) {
@@ -167,18 +186,25 @@
             $cmoptions->questionsinuse = $attempt->layout;
         }
 
-        if (!isset($this->catrandoms[$question->category][$question->questiontext])) {
+        // We should get list of usable questions in 2 cases:
+        // 1. it isn`t already cached in $this->catrandoms;
+        // 2. all questions in cached version are already used. 
+        //     If we run out of available questions in the middle of attempt generation we should call get_usable_questions_from_category
+        //       once more to fallback on using questions from previous attempts
+        if (!isset($this->catrandoms[$question->category][$question->questiontext]) || 
+        (count(array_diff($this->catrandoms[$question->category][$question->questiontext], 
+          explode(',',$cmoptions->questionsinuse))) == 0)) {
             $catrandoms = $this->get_usable_questions_from_category($question->category,
-                    $question->questiontext == "1", $cmoptions->questionsinuse);
+                    $question->questiontext == '1', $cmoptions);
             $this->catrandoms[$question->category][$question->questiontext] = swapshuffle_assoc($catrandoms);
         }
 
         while ($wrappedquestion =
                 array_pop($this->catrandoms[$question->category][$question->questiontext])) {
-            if (!ereg("(^|,)$wrappedquestion->id(,|$)", $cmoptions->questionsinuse)) {
+            if (!ereg("(^|,)$wrappedquestion(,|$)", $cmoptions->questionsinuse)) {
                 /// $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]