MDL-48924 backup: Fix some get_file_packer() calls for enabletgzbackups

course/externallib.php

@@ -1028,7 +1028,7 @@ class core_course_external extends external_api {
 
         // Check if we need to unzip the file because the backup temp dir does not contains backup files.
         if (!file_exists($backupbasepath . "/moodle_backup.xml")) {
-            $file->extract_to_pathname(get_file_packer(), $backupbasepath);
+            $file->extract_to_pathname(get_file_packer('application/vnd.moodle.backup'), $backupbasepath);
         }
 
         // Create new course.

course/tests/courselib_test.php

@@ -1726,7 +1726,7 @@ class core_course_courselib_testcase extends advanced_testcase {
         $bc->execute_plan();
         $results = $bc->get_results();
         $file = $results['backup_destination'];
-        $fp = get_file_packer();
+        $fp = get_file_packer('application/vnd.moodle.backup');
         $filepath = $CFG->dataroot . '/temp/backup/test-restore-course-event';
         $file->extract_to_pathname($fp, $filepath);
         $bc->destroy();

lib/tests/questionlib_test.php

@@ -186,7 +186,7 @@ class core_questionlib_testcase extends advanced_testcase {
         $bc->execute_plan();
         $results = $bc->get_results();
         $file = $results['backup_destination'];
-        $fp = get_file_packer();
+        $fp = get_file_packer('application/vnd.moodle.backup');
         $filepath = $CFG->dataroot . '/temp/backup/test-restore-course';
         $file->extract_to_pathname($fp, $filepath);
         $bc->destroy();