Emoji support for old browsers

[superpoincare]

I have observed that IE8, emoji don't display in some cases.

Here is an example: ​http://output.jsbin.com/punabekoli

The html for jsbin is the html output of Twenty Seventeen hosted on wp-themes.com with a minor modification that one emoji has been adding as the first para. (the rainbow flag emoji).

Screenshot generated here: ​https://www.browserstack.com/screenshots/67742ee3bcfd15a08012353603ecedf3b86db65a

I made this work by adding this code on console log:

var elements = document.getElementsByTagName("body")[0].getElementsByTagName("*");

for( var i = 0; i < elements.length; i++ ) {
	twemoji.parse(elements[i])
}

This can be resolved by using a test for old browsers such as for IE<=8

document.all && !document.addEventListener;

or more generally

"visibilityState" in document

and modifying L122 of wp-emoji.js or ​https://github.com/WordPress/WordPress/blob/master/wp-includes/js/wp-emoji.js#L122

[desrosj]

Thanks for the detailed ticket @superpoincare.

Starting wth version 4.8, support for Versions of IE < 11 has officially been dropped. I am going to close this out, but if a committer feels strongly about fixing this they can reopen it.