Inserting emojis that uses 4-byte utf-8 does not work with MySQL

Confirmed on nightly instances: I can't post a message to Forums with a 4-byte emoji to Sakai 11. To Sakai master the emoji is stripped as expected and my post succeeds.

Yes, let's backport this fix to 10.x. Can someone confirm this works on Sakai 11?

We just had a failure locally on 10.x because an email for the email archive tool contained an emoji and it failed to get inserted into the DB.

It looks like as of MySQL 5.7.7 the large_prefix is default to be on, and the old prefix size (767) is deprecated. So I think this plan is

Sakai 11, have a property that will remove 4-byte utf-8 characters (or convert to something else) on by default. Shouldn't be needed for Oracle though.

In Sakai 12+ maybe have a complete conversion for people running with this property or MySQL 5.7.7+.

Yeah, that sounds like a good quick fix for 11. What would we replace them with, A space? Some other character? It looks pretty straightforward. But I'd take the patch if they had something in production too.

http://stackoverflow.com/questions/12013341/removing-characters-of-a-specific-unicode-range-from-a-string

Some patterns like this might be enough too, if we also don't care about a replacement.
byte[] converttoBytes = string.getBytes("UTF-8");
string = new String(converttoBytes, "UTF-8");

There is an emoji library (https://github.com/vdurmont/emoji-java) that can remove emojis but I know there's characters outside of the emoji range that would also cause problems.

This article is the more appropriate one for this case.
http://stackoverflow.com/questions/12867000/how-to-remove-surrogate-characters-in-java