To reproduce, open http://jsfiddle.net/0jjnaghw/
Error is logged to browser dev tools (in Chrome & Firefox, somehow not in Safari).
Happens on v15.0.0-rc.2 and on latest master version.
The assignment of additional event data to the newly created SyntheticEvent triggers a console error:
|
assign(event, eventData); |
"Warning: This synthetic event is reused for performance reasons."