A more proper fix for the tiling->unsplit bug (#334)

[kristopolous]

As discussed over in #334, my patch was merely an unacceptable papering over of the crash and not a fundamental fix. Depending on code paths this can manifest in other ways.

The palliative care I did in #334 does alleviate the most irritating of the symptoms but it is by no means a fix and this placeholder reminds future humanity of this albeit at a lower priority.

tl;dr? bug still opened, not as severe. fix if able.