MDL-28180 backup - on restore always prevent completion_aggr_methd dupes

This covers the last case where dupes could be happening in the
completion_aggr_methd table: Restoring one complete course into
an existing one, adding information. Now we always check if the
aggr_method exists before inserting it.

backup/moodle2/restore_stepslib.php

@@ -1805,15 +1805,20 @@ public function process_course_completion_aggr_methd($data) {
 
         $data->course = $this->get_courseid();
 
-        $params = array(
-            'course' => $data->course,
-            'criteriatype' => $data->criteriatype,
-            'method' => $data->method,
-            'value' => $data->value,
-        );
-        $DB->insert_record('course_completion_aggr_methd', $params);
+        // Only create the course_completion_aggr_methd records if
+        // the target course has not them defined. MDL-28180
+        if (!$DB->record_exists('course_completion_aggr_methd', array(
+                    'course' => $data->course,
+                    'criteriatype' => $data->criteriatype))) {
+            $params = array(
+                'course' => $data->course,
+                'criteriatype' => $data->criteriatype,
+                'method' => $data->method,
+                'value' => $data->value,
+            );
+            $DB->insert_record('course_completion_aggr_methd', $params);
+        }
     }
-
 }