Cannot add an answer if the topic and the forum are created by the same (another) user

[ilieandriuta]

STEPS TO REPRODUCE

1. Go to a forum created by another user
2. Click on a topic (also created by the same user)
3. Click 'Add answer' button and write an answer
4. Click 'Add answer'

EXPECTED RESULTS

The answer is added.

ACTUAL RESULTS

The answer is not added on the page, although the page for the answer appears in the Navigation Panel.
The issue seems to reproduce if both the forum and the topic are created by the same user (different by the answering user), otherwise, the answer is added.

Environment: Windows 10 Pro 64 bit, Chrome 65

[acotiuga]

The fix for #8 also solve this issue. JavaScript errors caused by the bad answer ids are gone. Cannot reproduce the issue.