Fix test-case construction by giving old nodes the correct nodename.

question.php

@@ -96,7 +96,7 @@ class qtype_stack_question extends question_graded_automatically_with_countback
     public $inputs = array();
 
     /**
-     * @var stack_potentialresponse_tree[] STACK specific: respones tree number => ...
+     * @var stack_potentialresponse_tree_lite[] STACK specific: respones tree number => ...
      */
     public $prts = array();
 
@@ -764,7 +764,7 @@ class qtype_stack_question extends question_graded_automatically_with_countback
     public function is_complete_response(array $response) {
 
         // If all PRTs are gradable, then the question is complete. Optional inputs may be blank.
-        foreach ($this->prts as $index => $prt) {
+        foreach ($this->prts as $prt) {
             // Formative PRTs do not contribute to complete responses.
             if (!$prt->is_formative() && !$this->can_execute_prt($prt, $response, false)) {
                 return false;
@@ -991,7 +991,7 @@ class qtype_stack_question extends question_graded_automatically_with_countback
         // has_necessary_prt_inputs, and then does the computation, which ensures
         // there are no CAS errors.
         $result = $this->get_prt_result($prt->get_name(), $response, $acceptvalid);
-        return null !== $result->is_evaluated() && !$result->get_errors();
+        return $result->is_evaluated() && !$result->get_errors();
     }
 
     /**
@@ -1130,7 +1130,7 @@ class qtype_stack_question extends question_graded_automatically_with_countback
             $p = new prt_evaluatable($this->get_cached('prt-signature')[$name],
                 $prt->get_value(), new castext2_static_replacer($this->get_cached('static-castext-strings')));
             if (isset($prts[$name])) {
-                // Always manke sure it get called wit simp:false.
+                // Always make sure it gets called with simp:false.
                 $session->add_statement(new stack_secure_loader('simp:false', 'prt-simplification'));
                 $session->add_statement($p);
             }

stack/potentialresponsenode.class.php

@@ -421,7 +421,7 @@ class stack_potentialresponse_node {
 
 
     /**
-     * @return object with fields for the branches for the compiled PRT upgrade
+     * @return object with fields for the branches for the compiled PRT upgrade.
      */
     public function summarise_branches_extended() {
         $summary = new stdClass();

tests/helper.php

@@ -2615,6 +2615,8 @@ class qtype_stack_test_helper extends question_test_helper {
             $newprt->autosimplify = $oldprt->get_simplify();
 
             foreach ($oldprt->get_nodes() as $nname => $oldnode) {
+                // Make sure old nodes have the correct nodeid set.
+                $oldnode->nodeid = $nname;
                 $newnode = $oldnode->summarise_branches_extended();
                 // In the new world we don't parse these to AST-containers in general execution
                 // as that is a waste of time, we only do that during compilation of the whole PRT.

tests/question_test.php

@@ -154,8 +154,11 @@ class question_test extends qtype_stack_testcase {
         $q = $this->get_test_stack_question('test3');
         $q->start_attempt(new question_attempt_step(), 1);
 
-        $this->assertEquals(array(2.5 / 4, question_state::$gradedpartial),
-                $q->grade_response(array('ans1' => 'x^3', 'ans2' => 'x^2', 'ans3' => 'x', 'ans4' => 'false')));
+        $result = $q->grade_response(array('ans1' => 'x^3', 'ans2' => 'x^2', 'ans3' => 'x^2', 'ans4' => 'false'));
+        $this->assertEquals(array(2.5 / 4, question_state::$gradedpartial), $result);
+
+        $result = $q->grade_response(array('ans1' => 'x^3', 'ans2' => 'x^2', 'ans3' => 'x', 'ans4' => 'false'));
+        $this->assertEquals(array(2.5 / 4, question_state::$gradedpartial), $result);
     }
 
     public function test_grade_response_test3_incomplete() {