"Cannot read property '0' of undefined" error when stacked column chart is resized

[peter-scarab]

For a stacked column chart which is periodically updated, when the browser window is resized horizontally and the chart tries to change its width accordingly, a "Cannot read property '0' of undefined" error happens frequently.

In addition, when this happens, the points newly added to the second series start to appear on the column left to the last column, instead of the last column.

Demo: http://jsfiddle.net/peter_scarab/LLExL/5171/
Browser: Chrome 44
Tried with both the current master and bugfix branches.

[pawelfus]

Workarounds:

• disable animation: http://jsfiddle.net/LLExL/5173/
• rebuild stacks manually: http://jsfiddle.net/LLExL/5174/ (I think this may cause artifacts)

Internal note:
Similar issue to #4557 - in short: we use series.index and point's index (i) from series.points array to get stack and corresponding points (this line) . In fact, series.points array may be unsynchronized - in #4557 for example we remove points which are inside the break so we needed to rebuild stacks.
I tried to use x-value instead of i, but this breaks multiple stacked points with the same x-value. We can not use point.index because dataGrouping doesn't provide such information. Any insights and/or suggestions?

[TorsteinHonsi]

What about using the x value plus som indicator in case the of multiple stacked points? So if the x value for that series has been taken before, we add 1,2,3,4 etc? It's just a thought, I don't know if it works well...

[pawelfus]

Let me know what do you think. I will write a test for that case if this is fine.

[pawelfus]

Solution above is more generic - we can revert #4557 commit, unless you think this is a good idea to rebuild stacks after modifying points array. We don't need to do that, but it will release a bit of memory (since some of stacks will disappear when are created inside the break). However, we would need to rebuild stacks so it would require extra CPU (a bit, but still!) ;)

[TorsteinHonsi]

Yes, it's probably better to revert the #4557 commit to save CPU.

Let me know what do you think. I will write a test for that case if this is fine.

It seems like a robust solution. Maybe there's room for micro optimization, like constructing the empty stackIndicator, and generating the key?

[pawelfus]

Done in this commit and this one. I wasn't sure about generating the key so it's split in two commits, in case of reverting. Thanks!

[TorsteinHonsi]

Excellent, thanks! I pulled the fix and the optimizations and reverted the 4557 fix.

[shashivardhan]

I still see a similar problem when using highstock with stacked bar chart and scroll bar enabled, which has 100 categories.
https://jsfiddle.net/shashi3337/5xn92uht/1/
When I am using the scroll, I don't see the stacked bar on the chart and when I scroll back to initial position I'm getting this error
"Cannot read property '0' of undefined" error when stacked column chart is resized"

[pawelfus]

Hi @shashivardhan - it's a bug in categorized axis, setting cropThreshold resolves the issue: https://jsfiddle.net/5xn92uht/5/ I see you reported this here: #7944