On a subfolder install site I noticed that the avatar letters were broken in quotes.
I don’t really know, but I think that Rails.root in line 124 needs to be replaced with Discourse.getURL (which makes me wonder about the other 71 files that refer to Rails.root)
Note to others: You’ll need to rebake after you do this upgrade to fix the avatars in existing posts. (I can’t find simple instructions for doing a simple rebake; doing rake posts:rebake_match["quote"] is probably better anyway rake posts:rebake_match["[quote"] might be better still, but it looks funny.)