Top border line is missing when yAxis.reversed is set to true

[ktakahashimtb]

https://jsfiddle.net/ktakahashimtb/9mhrqtbg/

I'm using grouped_categories.js with Highcharts Heatmap, which works pretty nicely together. I ran into this issue with missing a border line at the top when yAixs.reversed is set to true. After some investigation, I found that the line which should probably go to the top is rendered at the bottom.

With making a few changes in the code, I could make the top border line to appear with y-axis reversed.

https://jsfiddle.net/ktakahashimtb/c96dqghu/9/

Here are the svg path instructions drawing the lines, taken from the both examples above. The very first line is where the difference is.

[top border line is not showing]
M 124 329 L 14.765625 329
M 124 122 L 76.3125 122
M 76.3125 191 L 14.765625 191
M 124 191 L 76.3125 191
M 76.3125 191 L 14.765625 191
M 124 260 L 76.3125 260
M 76.3125 329 L 14.765625 329
M 124 329 L 76.3125 329
M 76.3125 329 L 14.765625 329
M 76 53 L 76 329
M 15 53 L 15 329

[top border line is showing with modified code]
M 124 53 L 14.765625 53
M 124 122 L 76.3125 122
M 76.3125 191 L 14.765625 191
M 124 191 L 76.3125 191
M 76.3125 191 L 14.765625 191
M 124 260 L 76.3125 260
M 76.3125 329 L 14.765625 329
M 124 329 L 76.3125 329
M 76.3125 329 L 14.765625 329
M 76 53 L 76 329
M 15 53 L 15 329

[KacperMadej]

Hi @ktakahashimtb

Thank you for reporting the problem.