Pasting UTF-8 into a posting can return error

I was testing UTF-8 support, because we need to use it. Pasting UTF-8 into the posting seems like it can return errors and result in some inconsistent database state.

1. Go to http://www.unicode.org/standard/WhatIsUnicode.html
2. Copy text from the "Translation" navigation bar on the left of that page down to Greek (monotonic).
3. In a new posting window of the phpBB 3.0.6 forum, paste that text.

The system sends you this error message:

General Error
SQL ERROR [ mysql4 ]
Incorrect string value: '\xF0\x90\x90\x8E\xF0\x90...' for column 'post_text' at row 1 [1366]
An SQL error occurred while fetching this page. Please contact the Board Administrator if this problem persists.

I'm pretty sure that the UTF-8 text that was pasted is legal UTF-8.

The first time I did this, it created a line in the forum index, but then said no such posting exists when I clicked on it. This morning it seems to have not created a post.

I suspect that your UTF-8 support (or perhaps MySQL's support?) is barfing on the Deseret text. I.e., Plane 1 characters. If you remove that line from your pasted text before submitting the post, there is no error.