Avoid IE9 activeElement of death

[kristerkari]

I was testing this polyfill on IE9 and noticed that IE was throwing "SCRIPT16389: Unspecified error". This only happened when I used an iframe to load the page that had the polyfill in use.

Turns out that the error gets thrown if document.activeElement is asked inside an iframe while the page is loading. jQuery already fixed this, so I use the same fix for placeholders.js and after that the page started working normally.

More info:
http://bugs.jquery.com/ticket/13393
jquery/jquery@85fc587

[jamesallardice]

Good find! Thanks. Did you notice that your commit is not associated with your GitHub account? If you want to be credited in the contributors page of the repo you'll have to set your git username/email to match your GitHub account (with git config), amend the commit and then force push.

Let me know if you don't care and I'll go ahead and merge as it is. Thanks again.

[kristerkari]

@jamesallardice You can just go ahead and merge it. :)