Chart update breaks custom tooltip render

[Odrin]

Expected Behavior

Custom tooltip function executes when mouse leave chart element.

Current Behavior

Custom tooltip function do not executes if chart was updated inside config.hover.onHover callback.

Possible Solution

Problem appears here. chart.update() calls chart.tooltip.initialize(); which resets this._lastActive field and cause false negative result here; Simple solution is just replace this line with this._lastActive = this._lastActive || [];.

Steps to Reproduce (for bugs)

https://codepen.io/anon/pen/qzpPeb

1. Hover any chart element
2. Move cursor out of chart

Context

Environment

• Chart.js version: 2.8.0
• Browser name and version: Google Chrome Version 75.0.3770.100 (Official Build) (64-bit)

[slavaschmidt]

The same cause leads to the tooltip staying on the screen sometimes ignoring mouseout event.

It happens if the tooltip is already displayed and one of the following actions is done in the code: resetting tooltip, updating chart or chart config.

[etimberg]

In v3 we've rewritten the tooltip to be a plugin. I quickly tried to port the test case over, but it's quite complex. Saving this as a note to come back and try it.