Ok, apparently this is quite an old bug, funny that we never noticed this before...
I was not able to find the revision that introduced this but I still had it in
919bf6ac0d211fa6a7a6cffa09adfcdb9863f584
Date:   Sun Jun 9 21:20:21 2013 +0200
    map: level 12: disable infinite running.

the bug seems not to be present in a made-compile version of 0.15.1 though
(0.15.1 + some commits added which were intended to make some 0.15.2 release at
some point).