[exim] Behaviour change in 4.83?

Hi,

I've noticed that my mime checking is not working as expected since I
upgraded from 4.82.1 to 4.83 (on Arch Linux if that is significant).

Starting to try and work out why, I've logged $mime_filename for all
attachments. I see that it is now quoted but looking back through older
logs, it wasn't before.

I can't see anything relevant in the changelog so I see 3 possibilities:

1. I'm being dense - this is always possible as I must admit to finding
exim conditions hard to get my head round. I don't think so as I've
only had to touch simple config so far here.

2. It's an intentional change which I haven't found any documentation
for, in which case I'll work on my config.

3. It's not supposed to happen, in which case I can either live with it
(low email volumes make this plausible if not desirable) or I'll work on
my config and then revert the changes when the behaviour changes back.

I can post the relevant log lines from my config but they are just a
string including $mime_filename.

Hopefully someone with deep enough knowledge can help me out here. TIA,
George.