Selecting bars 'above the bar'

This seems to be something I run into with every charting tool I've ever used - so I'm getting-used to fixing it ;0

There's a problem with selecting/clicking bars which are very short or even 'empty' - because selecting/clicking acts on the visible bar rather than the 'space above the bar' - and there are definately use-cases for wanting to interact with those (and tooltips work with that use-case!)

I hacked a fix into c3_chart_internal_fn.isWithinBar to ignore 'y' position - that suits my purposes but it doesn't consider rotated charts or stacked bar charts - please consider an enhancement to enable interaction with 'empty bars' (an bar option for 'select column/data-only' perhaps?)

I note that the 'event columns' would probably be the simplest way to do this but there may be more things I've not considered with this?

Thanks