The figure-mode cursor test covered the *vertical* marker, which is one time
shared by every row. A horizontal ruler is the other half: its y is on that
row's own axis, so two rows' rulers are two different values, and every row's
has to be drawn in its own band. A host that puts two rulers on every plot
(`udpscope`'s cursors pane) needs exactly this, and had no test for it.
It asserts the strokes only -- the ruler's value label goes through the text
path, which this case is not about, so it uses the harness's no-atlas backend.
Martino Ferrari
523446d08f