scattergl hover error with nulls

[bhogan-mitre]

It appears that null values are not handled well by scattergl. The data that is present is displayed as expected, for example 3 of 4 points are shown in the screenshot below. However mousing around the plot area throws a lot of errors from the hoverPoints function. For example, Uncaught TypeError: Cannot read property 't' of undefined.

Reproducible example:
https://jsfiddle.net/bhogan_mitre/u41pn9eo/

I believe this is the underlying function at fault: https://github.com/plotly/plotly.js/blob/master/src/traces/scattergl/hover.js#L15

Would it be appropriate to add some checks in that function on cd before trying to access cd[0]? I have also seen errors further down where it makes it past this line:

var stash = cd[0].t;

but fails here:

var x = stash.x;

I will note that this is only an issue with scattergl and not the normal SVG scatter.

[etpinard]

Thanks very much for reporting!

[etpinard]

Looks like this is regression from 1.45.0.

Things were working ok in 1.44.4: https://codepen.io/etpinard/pen/VwZgjom?editors=1010

[antoinerg]

It looks like it was working in 1.46.1: https://codepen.io/antoinerg/pen/mdbvrBx?editors=1010
and that the regression was introduced in 1.47.0: https://codepen.io/antoinerg/pen/BaBMLmq?editors=1010

[etpinard]

Interesting. It's failing in 1.45.0 though: https://codepen.io/etpinard/pen/NWKoRMJ?editors=1010

[antoinerg]

Oh, I'm sorry, disregard #4212 (comment)