Forum posts are counted twice in Statistics

Viewing stats for a user (Home > Courses > [course] > Reports > Statistics) shows double the number of forum posts as they have actually made, as shown in:

• the student outline report (Home > Courses > [course] > Participants > teststudent1 test > Reports > Outline report), and
• the course logs (Home > Courses > [course] > Reports > Logs)

This seems to be because posts are logged as two events:

1. "Some content has been posted.
2. "{Discussion,Post} created"

The statistics pages present the two events as if they were separate posts.

I guess a fix for this would be in lib/statslib.php, filtering out one of those two event types when compiling the stats to the stats_user_{daily,weekly,monthly} tables.

Attached screenshots illustrate stats page with 2x posts compared to logs and student outline.