One obvious use case is rendering a text that's just a bunch of \n
characters. With the current code, it would result in a completely empty
rectangle no matter how many newlines there would be, which isn't right
because -- even if nothing is actually visible -- it would break
anything that relies on the bounding rectangle for alignment and
positioning of other content.
Another case is for example the Ui library, which -- once ported to
use the new Renderer instead of the lower-level APIs -- wants to use the
bounding rectangle for cursor and selection positioning. And if it would
be empty for empty text, it'd mean empty input boxes would have
invisible cursor. Not good.
The old Renderer implementation seems to have handled this correctly --
but in f3d6ab4916, when porting to the new
APIs, I discarded that from the test, thinking it was some unnecessary
behavior. It wasn't, it was just never tested directly so I forgot it
was needed.
Vladimír Vondruš
be2f4971d8