Group page notifications sent of existing pages in a group to new group members

[Kristina Hoeppner]

Regression in Mahara master (to become 19.10).

When a group admin shares pages with a group before a group member joins, the new member receives notifications for all previously created group pages when they should only receive notifications for pages created anew after they joined. This can generate a lot of notifications in large groups, which should be avoided.

To replicate:

1. Set up a controlled group (easier to add people) and do not add normal group members. Make sure that page notifications can be received by everyone.
2. Create a page in the group.
3. Add another person to the group. Wait a few minutes until the cron had time to run. For me it was about 5 minutes.

Expected result: There is no "New access to page..." notification to the new group member.
Actual result: The new group member receives a notification about the existing portfolio.

[Lisa Seeto (lisaseeto)]

This bug could not be replicated.