A share child was drawn in the measuring room and again in its slot, and
one record holding two questions made every local change under it defer
to the span. Where a rule or a hint gives the length along the span, the
first ask answers nothing the rule does not, so the child is asked once,
in its slot; the widgets that always report the whole of their box now
say so. A hint with a fraction resolves against the frame and pins it.
The dump rig prints every cold layout so a change to it shows in a diff.