Circles don't respond to events on the stroke area

[stevage]

mapbox-gl-js version: 0.40.1

Steps to Trigger Behavior

1. https://codepen.io/stevebennett/pen/NaYaLv
2. Notice how hovering over the green border doesn't change the interior color.

Expected Behavior

Hovering over the stroke part of the circle would trigger events.

I'm working on a map with very thick borders like that.

[anandthakker]

👍 thanks for the report & example @stevage

[stevage]

For comprehensiveness I'll point out that a workaround is to use two circle layers of different radius rather than a stroke outline, but there may be cases where that's inconvenient or worse for performance or whatever.