Unable to exit boost when series contains null points.

[karolkolodziej]

Expected behaviour

When there are fewer points than boostThreshold chart should exit the boost module.

Actual behaviour

When one series contains null points, and after zooming and having fewer visible points than the boostThreshold the chart is still boosted.
When the null series is not visible on the chart the issue is not visible.

Live demo with steps to reproduce

https://jsfiddle.net/BlackLabel/no0txe2c/

Product version

Highcharts JS v10.2.0 (2022-07-05)

Affected browser(s)

All

[bre1470]

Which was the last version this was working? I am down until v9.0.0 and it is never switching back to non-boost after zoom.

As far as I know boost determines enter and exit depending on the data size, not the point size. Points are always empty in boost.

Okay, I see now that the null series is preventing an exit. Otherwise it would fall back to unboost points.

[karolkolodziej]

I think it has never worked correctly. I check multiple versions and I didn't find one working.

[bre1470]

Thanks for testing further. 👍

[bre1470]

After playing around I found a workaround. Settings the chart option results in the desired effect:

	boost: {
		allowForce: false
	}

https://jsfiddle.net/bre1470/4z3pmfnv/19/

[bre1470]

Related: #8164