Yeah I found out the same problem and was busy posting a new post of the issue and didn't notice there was one already.
Here's the same post anyways:
"Yo, today while writing my blog I crashed in a tiny bug here:
The smiley or the emoticon or whatever it is ":.done:" is messed up.
As it should show the "done-tick" it just ends up like this :
It doesn't indeed ruin the page but i just felt like "reporting" this
"