Steps to reproduce
==============

1. Create a course.
2. Add an image to a topic summary.
3. Add a page with an image.
4. Add a lesson. Add an image to a content page. (resolved in MDL-42212)
5. Add a wiki. Add an image to the first page.
6. Open the file picker from any of the added images.

Expected result
===========

All 4 images show up (in different folders) in the server files area of the file picker.

Actual result
=========

Only the images added to the topic summary and the page show up. The images added to the lesson and the wiki are not shown – not even if the file picker is opened from inside the activity.

It might not be a very realistic scenario to reuse an image added to a lesson or wiki page, but the behaviour feels inconsistent.