HMI needs extra clicking after weston 1.9

After updating the GDP to use weston 1.9, input focus and event routing behaviour appear to have changed.
The first click into a surface appears to do nothing. Subsequent clicks into that surface behave as normally.
My suspicion is that mouse button events aren't sent if the surface doesn't have pointer focus, and pointer focus is set by clicking on the surface, now.
I have not yet investigated this in detail.