Moodle XML question export/import does not include question-category idnumbers

The automated test coverage should be sufficient. If you want to test manually: Create a test course. Create a question category, and set its idnumber to 'catid'. Create a question in that category. Export the category in Moodle XML format. Create another course. Import the file you just exported into the question bank of the new course. Go to Question bank -> Categoryies and edit the imported category information. Verify that the imported category has idnumber 'catid'. (You could also, after step 4, look at the context of the export file and verify that it contains 'catid' in the right place.)