Moodle XML export for calculated question produces incorrect correctanswerlength

Calculated questions exported in Moodle XML format do not set the correct "Correct Answer Shows"

To reproduce:
Make a new calculated question.
Enter any name, question text "

".
Export question.

Expected: <correctanswerlength> tag set to 2 (the default value)
Actual: <correctanswerlength> tag is set to 1

Importing the exported XML confirms the problem:
Import the file you exported above.
Edit question.
Expected: "Correct answer shows" will still be 2 (as originally set)
Actual: "Correct answer shows" is 1

The value written out seems to depend on "Tolerance Type". It is 1 for geometric and relative regardless of the value set in writing the question. It is 2 for nominal regardless of the value set in writing the question.