Showing external tooltip on legend hover issue

[peteruithoven]

Expected Behavior

When I use tooltip.setActiveElements on legend.onHover and I'm using an external tooltip, it should show the tooltip.

Current Behavior

The externalTooltip handler is called, which would render the tooltip, but then it's immediately called a second time, where the second time the tooltip.opacity is 0.

Steps to Reproduce

Example: https://codepen.io/peteruithoven/pen/qBXMBNx?editors=0010
Hover over legend items, no tooltip will appear.
(console.log will show external tooltip function calls)
Initial setActiveElements and regular pie chart hovering does show tooltip.

Context

We sometimes have charts with very low values, so we need an additional way to show the tooltip.

Environment

• Chart.js version: 3.5.1
• Browser name and version: Firefox

[peteruithoven]

Looking into the Chart.js tooltip code it seems to call afterEvent, which calls handleEvent which calls update, which calls extenal.