Bar chart bars overlapping when data is a little spread out

Bar chart bars overlap each other when the data isn't as nicely spread out, but sporadic. Here's a fiddle of the issue. http://jsfiddle.net/Ljennqjw/1/
notice how the bars on the right all overlap.

Reproduce the overlap with the linked JSFiddle, focusing on the bar chart behavior when values are sporadic rather than evenly spaced. Trace the chart's bar layout and spacing logic, then verify that the bars no longer overlap for the reported data while preserving normal bar-chart rendering.

Written by the indexing model from the issue text.