Limit number of tracker submissions

• Regression
• Less than 30-minutes fix

A check box to mark the tacker can only be submitted once per person, like in the quiz feature, but with trackers.

I've tried everything I can think of that was written in every tracker help page to force only one submission per user. (not the same as one entry per user, since it seems I can re-submit the form over and over to modify the answer.)

Tested in trunk as of Jan 19th 2016 (r57256) and I confirm that there is some regression bug at least in trunk: standard registered user is able to submit a new item even if the setting to allow just one item per user or ip is enforced.
To reproduce: login as
u: user1
p: user1
(plain registered user)

And go to

http://duqtape-11783-5792.show.tikiwiki.org/tiki-view_tracker.php?trackerId=1

where you will be able to insert new items, when you shouldn't, since the tracker setting "Only one item per user or IP (The tracker needs a user or IP address field with the auto-assign set to Creator)" is enabled, and that user field is set as required.

You can admin the site with:
u: admin
p: 12345

It seems to be fixed by amoeba32 in a recent commit:
http://sourceforge.net/p/tikiwiki/code/57480/

I'll upgrade the test site here to retest. done

Fixed, even if the user attempting to add a new item (once a previous one was added already) did not see any error message, and might think that the changes were updated (like casting a new vote replacing the old one, in the use case set in the show.t.o instance)
http://duqtape-11783-5792.show.tikiwiki.org/tiki-ajax_services.php?controller=tracker&action=insert_item&trackerId=1&modal=1

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org