Long links format with spaces?

Long URLs appear to format with spaces in the output, which makes them look wrong. The link goes to the right place, but if you cut and paste you may be on your own. Here's an example post in the testing forum: Long link test.

Here's a snapshot from Firefox of the link with the space in it and the source to the page showing that there is indeed a space in the link text, it's not some kind of weird browser formatting issue:

But here's what it looks like from the forum editing interface. No space:

What gives? This has been going on since the upgrade, I think.