After export from secondary glossary to main glossary images won't display

1. Create a new secondary glossary in a course.
2. Add an entry to this glossary that includes an image as part of the HTML definition.
3. Create a new main glossary in the same course.
4. Go to the secondary glossary and click on "Export to main glossary" (plus icon) and "Continue".
5. The image will disappear in the secondary glossary and won't be displayed in the main glossary neither.

(6. You can go to the main glossary and click on "Delete" (plus icon) and "Continue". Then the picture in the secondary glossary will be displayed properly again.)