Add an image on a link doesn't work anymore

I just updated the trunk and now it's not possible to add a clickable image.

Before, I did to display image with a link:

"!image_url!":url

Now with the trunk, it displays the link with this text:

!image_url!

It seems that adding spaces before and after the ! ! fix the problem.
But is it normal? is it a bug?

Doesn't work:

"!image_url!":url

work:

" !image_url! ":url

Since it's a regression after r2677, I submit an issue #3437

This problem also happen with center image with p=.

(1-2/2)