Attachement with "+" in the name doesn't work

If you upload an attachement with "+" in the name, it's uploaded well but it result in an final url with a "+" inside that is not recognised if you click on it it result in a wrong page "The attachment does not exist."

eg : "toto+tata.jpg" as attachment

It's a bit weird to put a + in a file name, but some of our users did it resulting in this bug