I didn't think to look for a previous fix, thanks for finding this commit id!
I did a quick look at the places found with "git grep isspace" yesterday. I agree with the comment from commit 9ae2661: "I've left alone isspace() calls in places that aren't really expecting any non-ASCII input characters, such as float8in()." There are a number of other calls where I think it would likely be safe, and possibly even a good idea, to replace isspace() with scanner_isspace(). However, I couldn't find any where I could cause a bug like the one I hit in hstore parsing.
