This fixes a mild regression in 6bd2a0315ff56a20027074d65ccaa094bd35e63f,
which fixed a bigger bug. That change added the event parameter to
add_alert_word(); this change updates one of the callers to now
supply it.
(imported from commit c6375abb8bd22d12c538cd7439462aae4665ee38)
The global in question was `event`, set to:
MouseEvent {dataTransfer: null,
toElement: button.btn btn-mini add-alert-word,
fromElement: null, y: 442, x: 763…}
in Chrome. This does seem to be the correct event.
In Chrome, this global variable existed, so the code path didn't error
out. In Firefox, the global variable didn't exist, causing adding
alert words to fail.
(imported from commit 6bd2a0315ff56a20027074d65ccaa094bd35e63f)
Tim Abbott
Steve Howell
Jessica McKellar
Allen Rabinovich