highslide-software/highcharts.com — pull request #3432 by fabriziofortino (2014-09-12 10:37:08+00:00)
Title: fixed error on heatmap used through highstock instead of highcharts

Heatmap works fine when used with highcharts

http://jsfiddle.net/highcharts/4aqhB/light/

But does not work when used with highstock

http://jsfiddle.net/fabriziofortino/2qvgdnvd/